I concentrate soley on debuff. ED Enhancement Distribution, not the other one Bob Dole has, works excellent. I only play MM's and trap are usually my forte. My current set is lvl 33 Merc/Traps. All my mercs are set to a balanced 5 slots. Depending on the attributes they are mostly set for debuff and the trap side. Your mercs sport several trapping goodies and if SLOTTED right the effects are thru the roof.
My specops are SO ACC, SO HOLD, SO IMMOB, SO DEF DEBUFF, SO TO HIT DEBUFF. When the grenades go flying, all hell breaks loose. Additionally since the upgrades are usually DMG or TRAP form, I make the final upgrade so that it recharges instantly this can save ur butt in a pinch when recalling the commando or spec ops.
My only beef is AV missions shred your team in one hit. I think the pets need to be treated more like actual players, and certainly added enemies. I usually solo, so imagine entering a building as one but calling 6 of your buddies to come help. Its a walk in the park. I dont want the difficulty in color to go up, just more villains. The debuffs are like magic with your pets so why arent the defenses? The Bubble machine aha shield generator is a joke. Why not replace it with a quiet version of the targeting drone? God knows the soldiers miss alot.