There's a video available of two of the developers playing on Tactical difficulty, and (not trying to insult them, but..) they were frequently not communicating their intentions to each other very well, nor taking the battles very seriously, yet still managing to win. So, I can't imagine that you have to min/max to win.
My only concern/hope is that opponents aren't constantly resorting to throwing grenades around with pin-point accuracy, as that just seems like a weak approach to increasing the difficulty.
I'll get to try it myself this weekend when a buddy and I fire up a co-op game, so I'm excited to test it out (as we found the original version of the game to be too easy).