As I continue to digest all the new abilities, rules, and models that have come out for Space Marines between the start of 8th edition and the recent Codex release, one of the things that struck is me is figuring out how to best use the new Primaris units and, in particular, how to integrate them effectively with different Chapter Tactics.
While I think (contrary to many opinions across the internet) that all seven Chapter Tactics are at least solid, if not outstanding, I also think that the new Primaris Dreadnought/Infantry can maximize their abilities when combined with certain Chapter Tactics.
Below are some ideas I have for synergizing different Primaris units with specific Chapters and the abilities they bring to the table:
 Iron Hands Redemptor Dreadnoughts — This may seem like an obvious one (given the IH’s affinity for vehicles in general and Dreadnoughts in particular in the fluff), but the Redemptor is already a beast, coming in at T7 13W and a 3+ armor save. Now, add in the 6+ “FNP” from Iron Hands Chapter Tactics and the Redemptor effectively has the equivelant of 15 wounds, putting it almost on Land Raider levels of durability (have an Iron Hands Librarian cast “Might of Heroes” on it and then it becomes T8, making it even tougher to damage, especially against S7/S8 weapons, plus it becomes even more dangerous in close combat).
In addition to Chapter Tactics, the Iron Hands have the unique stratagem called MACHINE EMPATHY, which enables a vehicle to ignore the penalty to BS for moving and shooting Heavy Weapons or advancing and shooting Assault Weapons, which synergizes quite well with the Redemptor Dreadnought, given the large number of weapons it carries on its chassis. If you load out a Redemptor with a Heavy Onslaught Gatling Cannon, an under slung Onslaught Gatling Cannon, two Fragstorm GLs, and the Icarus Rocket Pod, then it can move its full 8″ a turn and put out 18 x S5 AP-1 shots at 24″, another 2D6 S4 shots at 18″, and D3 S7 AP-1 shots with “Skyfire” a turn, making it an ideal platform for dealing with massed infantry and/or light enemy vehicles. Alternately, you can load this Redemptor in a Lucius Drop Pod (from FW) and bring it in turn 1 just outside 9″ from enemy lines, where it can unleash this massed shooting and then possibly even charge (cast Veil of Time on it by a nearby Librarian to get re-rolls for its charge distance), bringing even more “heat” into enemy lines right out the gate.
 Salamander Aggressors (with Flamestorm Gauntlets) — Another kind of obvious one, given that these are the main Primaris models armed with any form of flamer weaponry right now, which of course is the Salamander’s forte. In terms of Salamander Chapter Tactics, being able to re-roll 1 failed to hit and 1 failed to wound dice in the shooting phase is not that great on these Aggressors (they already auto-hit and re-rolling to wound with one flamer hit is nothing to write home about), but don’t forget these Chapter Tactics also work in the Fight phase, where the Aggressor’s S10 AP-3 D3 damage gauntlets really DO benefit from a free re-roll to Hit and to Wound each combat round.
Besides the bonus from their Chapter Tactics, the Salamander Unique stratagem, FLAMECRAFT, costs 1 CP and allows the chosen Salamander unit to add +1 to any Wound rolls made for Flamer Weapons in the Shooting phase. Even with a minimum squad of three Aggressors, that is 6D6 S4 hits, all with +1 to their to Wound rolls… add in a nearby Vulkan and you also get to re-roll all failed to Wound rolls with flamers as well, meaning that against all targets they auto hit and, against T3, they would on 97% of their hits, against T4 they wound on 88% of their hits, and against T5-7 they wound on 75% of their hits, making them absolutely devastating against almost all forms of infantry. Even in Overwatch, where you cannot use the FLAMECRAFT stratagem (it can only be used in your own Shooting phase), the Salamander Aggressors get to shoot twice (as long as they did not move in their turn), resulting in 12D6 S4 hits when they are charged, all with re-rolls to wound if Vulkan is nearby… in other words, it is basically suicidal to charge a Salamander Aggressor squad (equipped with Flamestorm Gauntlets and with Vulkan nearby) with anything short of T8 monsters/vehicles.
 White Scars Aggressors (with Auto Boltstorm Gauntlets/Fragstorm GLs) — Now, this might seem a bit of an odd choice, since Aggressors do not really epitomize the mobile warfare doctrine White Scars are known for, but upon closer examination White Scar Chapter Tactics actually benefit this version of Aggressors pretty solidly. Since all WS units add +2 to the Advance rolls, and Aggressors can Move + Advance and still shoot their Auto Boltstorm Gauntlets/Fragstorm GLs with no penalty to BS, this means they basically have a 8-13″ movement ability combined with an 18″ range on their shooting weapons, giving them a “threat radius” of 26-31″ every turn (or even further, if you use the new Repulsor tank to drive them up to enemy lines). Combine this with a nearby White Scar Warlord with the “Storm of Fire” WL Trait and a six man squad of Aggressors can drown your opponent in 36 + 6D6 Bolter shots a turn, with any 6+s to Wound becoming AP-1, which can devastate all forms of infantry in the open.
As for the second half of White Scar Chapter Tactics, the ability to Fall Back and then charge again in the same turn is a tremendous boon for Aggressor squads, since that enables them choose which combats they want to be in and also charge basically every turn, thus striking first with their 2 x S8 AP-3 D3 damage close combat gauntlets per model. Whether shooting or charging (or both), these variant of White Scar Aggressors could benefit tremendously from a nearby WS Captain and/or Lieutenant, since re-rolling 1s to Hit or to Wound can make their high volume of shooting and their potent close combat attacks that much more reliable all game long.
 Black Templar Reivers — While there are lots of different units that can benefit from the Black Templar Chapter Tactic ability to re-roll all failed charges, I think Reivers in particular can leverage this and other BT unique capabilities. When equipped with Heavy Bolt Pistols and Combat Knives, Reivers each have 3A base (4A on the Sergeant), so they are above average in short-ranged shooting and close combat right out the gate. Add in the ability to Deep Strike in 9″ away from the enemy turn 1 via Grav Chutes and you can rapidly get them in position to charge and use that BT Chapter Tactic to its full advantage. Finally, if you Drop Pod in Helbrecht, Grimaldus, and a Lieutenant right next to the Reivers on that same turn that they come in and attempt to charge, then they all gain re-rolls to Hit, re-rolls of 1 to Wound, Ld9, S5 in close combat, and the ability to generate even more attacks if they roll any 6+ to Hit. A 10 man squad of Reivers (with Helbrecht, Grimaldus, and a Lieutenant nearby) shooting and then charging, say, a 30 Boy mob of Orks, would get 10 x S4 AP-1 Heavy BP shots and 31 x S5 attacks, resulting in 25-27 dead Orks on average when the dust all settles.
Reivers used in this manner can effectively defeat enemy “bubble wrap” unit turn 1 while the rest of the BT army maneuvers into position to make their own charges and, in later turns, the Reivers can help force-multiply the rest of the Templar assault via their Shock Grenades (no Overwatch and -1 to Hit for the rest of the phase for any units hit by them) and their “Terror Troops” bubble (-1 Ld to any enemy units within 3″ of one or more Reiver squads). Also, given that they have T4 and 2W and are relatively cheap points-wise (at least compared to other Primaris units), Reivers provide an affordable method to keep enemy units occupied until follow on Black Templar “hammer” units (i.e. Terminators, Vanguard Vets, Assault Centurions, maxed out Crusader squads) can get stuck in and do what BT do best.
 Ultramarine Intercessors — Given their newly acquired “Objective Secured” status as a Troops choice, Intercessors particularly benefit from the Ultramarine +1Ld, making them excellent for camping on objectives until the very last man, especially with re-rolls from ATSKNF. Additionally, being able to fall back and still shoot benefits Intercessors significantly, since they are basically “Sternguard-lite” with their S4 AP-1 Bolt Rifles. Finally, the UM unique stratagem, SCIONS OF GUILLIMAN, costs 1 CP and allows them to re-roll ALL to Hit rolls for a single phase, making them significantly more potent, especially when double-tapping their Bolt Rifles. Throw in Guilliman himself nearby and Intercessors become a threat to even tough units like TEQs and light vehicles. For example, two full 10 man squads of UM Intercessors rapid firing at the following targets with Guilliman nearby produces the following, on average:
-T4 2W 2+ armor Terminators — 8-10 Unsaved Wounds
-T7 10W 3+ armor CSM Rhino — 8-10 Unsaved Wounds
-T5 10W 4+ armor DE Raider — 10-12 Unsaved Wounds
-T5 3W 3+ armor CW Wraithguard — 8-10 Unsaved Wounds
For a pair of basic Troop units whose main job is to hold Objectives, that is some very solid damage output every shooting phase, and yet another reason to run UM Intercessors.
 Imperial Fist Inceptors (with Assault Bolters) — Again, perhaps a little surprising here, but Inceptors can really do some effective work using Imperial Fist Chapter Tactics and abilities. For example, take a 6 man squad of IF Inceptors, all with dual Assault Bolters… this unit can Deep Strike, fall back from combat and shoot the same turn (thanks to the “Fly” keyword), move 10″ a turn, and has 12W at T5 and a 3+ armor save. On top of that, it can put out 36 x S5 AP-1 shots a turn at 18″ and ignores any enemy Cover bonuses, which makes it even more effective against massed light infantry (like Conscripts, Cultists, Gaunts, Orks Boyz, Necron Warrior phalanxes, CW Guardians, etc.) that are often used to “bubble wrap” opposing armies and which rely on cover to boost their survivability.
Finally, activate the Imperial Fist unique stratagem, BOLTER DRILL, on the squad and also boosts its shooting by +1 to Hit with a nearby Rhino Primaris (meaning that every 5+ grants you an additional shot) and you get an average of 40 hits from a single Inceptor squad. Against a 30 man Conscript squad in cover, that averages 22-23 Unsaved Wounds, followed by another Mortal Wound when the Inceptors charge (due to their “Crushing Charge” rule) and then 5-6 Unsaved Wounds in combat from the Inceptors… that is a total of 29 dead Conscripts on average, with the last model being wiped out by a failed Morale Check even if a Commissar is nearby (he executes the last man standing) and the enemy “bubble wrap” completely removed in a single turn. Alternately, against a MEQ squad, these Inceptors would average 13-14 Unsaved Wounds from shooting alone, so basically wiping out an entire squad plus of anything they are shooting at. Even against a tough unit like a CSM Daemon Prince, this unit would cause an average of 6-7 Unsaved Wounds from shooting, followed by an average of 1 Mortal Wound on the charge and then another 1-2 Unsaved Wounds in combat, killing the Daemon Prince outright before it even got to swing back in the Fight phase. As you can see, Bolter Drill and a supporting Rhino Primaris makes IF Inceptors VERY deadly to a wide range of targets (and they can get even deadlier, if you put your WL near them with the “Storm of Fire” WL trait).
 Raven Guard Hellblasters — While Raven Guard Chapter Tactics are outstanding on any unit that has access to them, they pair particularly well with the long range/high hitting power of Hellblasters and the special RG Stratagem, STRIKE FROM THE SHADOWS. Before the game begins, you can use STRIKE FROM THE SHADOWS to “Infilitrate” a Hellblaster squad 14″ away from an enemy unit that you really want to destroy… ideally, you put the Hellblasters into cover so that they have a 2+ armor save and, as long as they are more than 12″ from the enemy, they can maximize their survivability due to the -1 to Hit for any enemy units shooting at them. Turn 1, drop a Jump Pack Captain and Jump Pack Lieutenant in next to them and then unleash 20 x S8 AP-4 D2 shots at your chosen target, re-rolling 1s to Hit and to Wound. Shooting this powerful can devastate infantry of all kinds and can even take on things like 16W, T8, 2+ armor Land Raiders, with an average of 15-16 hits, 9-10 wounds, 7-8 Unsaved Wounds, and 15-16 damage total inflicted (i.e. if you are even average in your rolling, they just “one-shotted” a entire Land Raider by themselves).
Alternately, you can give the RG Hellblasters the Heavy Plasma Incinerators and deploy them normally, in cover deep in your own deployment zone (so again, 2+ armor saves and a -1 to Hit them for most enemy shooting). With a nearby Rhino Primaris to buff their BS (and make it impossible for them to Overheat their plasma weapons), a 10 man squad of Hellblasters with Heavy Plasma Incinerators in essence becomes a squad of 10 x BS2+ Lascannons, albeit with only 36″ range (vice 48″ normally) and D2 (vice D6 for a Lascannon) for each weapon (but they do also have AP-4, instead of AP-3 like normal Lascannons)… add in a nearby Apothecary to heal/revive any Hellblaster casualties and an Ancient with the Banner of Emperor Ascendant relic (friendly units nearby are immune to Morale tests and any nearby friendly infantry models that die get a “free” shot before being removed on a roll of 3+) and you have a very tough, very dangerous, long-ranged fire base unit that can take on a wide variety of units all game long.