I'm totally OK with Arkhah playing ninja on his own.  The elite squad does not lose much by his absence, and if he's able to be a ghost without them, more power too him.  That leaves one elite squad unled, but I THINK we're alright there.  (Darius would handicap an elite squad, by the way, because he'd let everyone know where they are... and their stealth is their best advantage... (as shooting first is a big advantage when you have next to no armor...)<br/><br/>As for blocking the corridors to the west, few things are better than keeping an entrance locked down then, say, a Walker with a multilaser on overwatch... ready to open up on full auto.  Anything that comes from the west would get cut to ribbons.  So as soon as we get into that room, I suggest that the two walkers switch from guarding the squads to covering the two west entrances... leaving the 4 squads and Sarah in her walker to liberate the imperial guardsmen.<br/><br/>Baring that, Darius and his squad would cover one, while the walker with them would cover the other, while the rest of you (with the remaining 3 squads and the 2 walkers) liberate the imperial guardsmen... Darius with his heavy bolter can lock down an entrance just as well as a Walker, really... so the choice would be, use a squad and Darius, or a walker for the job.<br/><br/>Of course, sending Arkhah alone to the west to cause chaos and death there probably would work just as well... as they'd hardly march a unit through an area where they're getting sniped from...<br/><br/>Never mind, I vote for Arkhah to cover our western flank as well... then we'd be at nearly full strength for assaulting the mutants in front of the Imperial guards.