I had a post half finished but I accidentally closed the window.
Haha, F'lickta as Bre'unor would be great.
For the Berserk/F'lickta I would suggest making the F'lickta swing faster during melee, or have a less of a chance of flinching when hit by an attack. If you pit a F'lickta vs. a Thrall one-on-one, the Thrall has a high chance of flinching the F'lickta to death during a melee battle. I'd use a vs. MaraMyth unit comparison, but most things tear apart F'lickta or aren't even close (F'lickta vs. Devlins
).
Warriors as Elite Pfhor are great, but once again they're glass cannons but I've found that even on Legendary (I mean Total Carnage) the Elite Phor can tear apart small groups of Devlins as long as they have a superiority of numbers (or the Devlin's have been weakened first by ranged units). I suppose a simple solution would be switching the Elite Pfhor/Warriors with the F'lickta/Berserks. Although really, another "Light" or "Dark" Marathon unit might be a better choice...like...a Phor Trooper or something. I'd say a Cyborg, but I remember the Cyborgs from the original SiTH would end up killing each other when they died because they'd explode and cause this large chain explosion.
...I was trying to figure out how to work the BoB pistol units in there but I can't think of anything....maybe Warriors instead?
EDIT: Oh...Warriors as Pistol BoBs and Berserks as Elite Phor?
Hunters are decent in bunches, but as you said the Hunters need some work. IMO, the delay between their shots is too long, perhaps making them fire faster or in short two or three round bursts?
As for Soulless perhaps instead of VacBoBs use Pfhor Troopers or Blue Phor (major projectile phor)? Although Pfhor Troopers fire grenades at long range and use a machinegun at short range they might be a bit over-powered, the Blue Pfhor fire energy shots at long range as their primary attack and have a melee at close range.
The only other suggestion I'd make is making the hero units Marines. Eg: the Warlock Hero a TOTZ Marine, the Archer Hero a SMG Marine, and so on and so forth.
Sorry for the long post, figured I'd get all the ideas I had out at one time.
. I didn't really notice it at first, until I played Gate of Storms (which strangely enough, is where you first see Devlins/Mykridia). The Devlins can get up onto "Soulless" only hills (which is normal) and then they were able to rain death down on poor Alric's head as he tried to shamble by. I thought it was taunting at first, then I noticed Alric's health dropping like a rock.