Horns of Doom
Warlord in front, casters in the middle, Fighter as rearguard, Assassin scouting and doing sneaky business off to the side. Allows a quick collapse in any direction to move the casters back and the armor forward with single shifts. Scouting will hopefully allow for at least warning and reaction time, if not outright counter-surprise.
Combat Array A: (standard combat)
Combat Array B: (zergling fight)