Following the logic that each attack against each squadron is a separate attack within a single attack action? That said, where does it say the concentrate fire command only applies to a single attack and not just the attacks made that turn? I ask because I have been looking through the rules reference, and I can't find anything limiting the order to one attack. Only the token is limited by what I can see.
The Rules Ref (p4) says "reroll ONE attack die in the attack pool" (my emphasis). Once you've used it for a reroll you discard the token, so you can't use it again.
Edited by Ghost Dancer