It appears more and more that the new Skitarii will be excellent allies, especially to any Imperial armies as they are “battle brothers” status with them.
1 – Anti-Flyer/FMC – One of the weakest parts of the DA codex is its lack of good anti-flyer capability. Outside of the option for Flak Missiles and Quad Guns on Aegis Defense Lines, Dark Angels have their Dark Talon and Nephilim flyers, but it is almost universally agreed that these flyers are underpowered and over-costed, making them a poor choice for competitive list building. With the option to take an Icarus Array for its main weapon load-out, the Onager gets the following:
-Daedalus Missile Launcher
48″ S7 AP2 Heavy 1 Skyfire
-Gatling Rocket Launcher
48″ S6 AP4 Heavy 5, ignores cover, Skyfire
-Twin Icarus Autocannon
48″ S7 AP4 Heavy 2, interceptor, Skyfire, twin-linked
Combine this with a squadron of 3 x Onagers and Dark Angels suddenly have an exceptionally potent, reasonably point-costed, anti-flyer/FMC option. Add in a Dark Angel Librarian with Prescience to Twin-Link the shooting of the entire squadron and you should be able to kill multiple flying units (vehicles and MCs) over the course of the game. To give an example, with Prescience, a squadron of 3 Icarus Array Onagers targeting an AV12/12/12 Stormraven should get 8 x S7 hits and 13 x S6 hits, in turn netting about 2 normal hull points and another 2 hull points with the Ignore Cover rule… after Jinking is accounted for, that means an average of 3 Stripped HPs, which translates into one dead Storm Raven (or Storm Wolf, or Heldrake, or Vendetta, etc. etc.).
2 – Neutron Laser/Rad Grenade Synergy — Another option for combining DA capabilities with support from Skitarii Onagers is equipping a squadron of 3 Onagers with the Neutron Laser (48” range, S10 AP1, Heavy 1, Small Blast, Concussive) and using in conjunction with a RW Black Knight squadron. First, move in range with the Black Knight and hit an enemy Monstrous Creature (i.e. Dreadknight, Riptide, Nurgle Daemon Prince, Necron C’tan, etc.) with at least one Rad Grenade from the RW GLs, thus reducing the target T by -1 to T5 or below…. Next, engage the same MC with the Onager squadron’s 3 x Neutron Lasers… you should be able to get at least 1-2 hits and 1-2 wounds… provided the target fails at least one cover/Invul save, it suffers ID and is removed from play entirely, since it is now (T5 from the Rad Grenades and the Neutron Laser is S10). Even if you engage something like a Wraithknight, which has T8 naturally and so can’t be IDed by this tactic, if a single wound gets through then the Concussive rule means that it is reduced to I1, allowing you to charge in and bring it down in close combat before it can swing back.
3 – TLed Heavy Phosphor Blaster and Banner of Devastation – If you choose to equip an allied Onager with the TLed Heavy Phosphor Blaster (36” range, S6 AP3, Heavy 3, Lumingen) , then you can target an enemy unit in cover… if you inflict at least on unsaved wound, the Lumingen rule means that target enemy suffers -1 to its cover save (with 3 shots and S6 AP3, even a single Onager is likely to achieve this)… once this is achieved, you can combine this with shooting from Dark Angel Bolters supported by the Banner of Devastation to “torrent” down enemy hordes very efficiently. For example, say you were engaging a 30 man, Fearless (thanks to attached Priest) AM “blob squad,” in cover behind an ADL, with a pair of DA Tactical squads supported by the Banner of Devastation… at BS4, that is 80 shots, about 52-54 hits, 34-36 wounds, and 17-18 dead Guardsmen after their 4++ cover saves were accounted for… add in the Lumingen rule from the Heavy Phosphor Blaster and now you get 80 shots, about 52-54 hits, 34-36 wounds, and 23-24 dead Guardsman, almost wiping the squad out entirely. As you can see, just by reducing enemy cover by -1 with Lumingen hits, you can greatly improve the efficiency of DA shooting, especially with high volume of fire units like Tactical Marines supported by the Banner of Devastation.
In summary, there are numerous ways to leverage the strengths/options of the Onager Dunewalker squadron as an ally to Dark Angel armies, and in turn the DAs can provide significant enhancements to the Onager’s capabilities as well.