Whatever done in the post, it's ok guys. No need to justify this or that - I'm ok with whatever you guys do. My character might get angry IC, but that's not me OOC. If it were me OOC, I'd say something, so no big deal at all. And as Shadow pointed out, the repercussions aren't going to be major most of the time. I'll do my best to make sure you guys got more to work with in posts in the future, though we're going to need posts to get rolling too. The thing that's come to mind is that the Aggressors are going to be the center of whatever we do; if they don't make a move first, then everyone else is going to be somewhat uncertain as to what to do. The closest IRL analog would be the squad's automatic weapons guy with the belt fed machine-gun. So yes, using one is, to a degree, a responsibility, and the pressure is on the Big Guys.
Even then however, there's ways everyone else can get around that I believe; the simplest would be to have the post revolve around them, saying that the character did this or that to the left, right or whatever of the Aggressor. Hope that helps.