Due to my unfamiliarity with him, I've been having trouble taking Crossfire seriously as a threat in Hawkeye and Mockingbird. I don't think I've ever read a story he was in, so there's no history to convince me he's a dangerous guy. No, shooting Mockingbird's mother doesn't count. Despicable act, yes, act capable of marking him as a threat to super-heroes? No.
The costume doesn't help either. The red "X" on the eyepiece especially, seems like it would obscure his vision. It's far too wide to serve as good crosshairs. Plus, just a little turn and the "X"es on his costume would become crosses, meaning he's either part of a militant faction of the Red Cross, or some cadet from the Swiss Army that showed up in that one episode of The Tick.
Maybe it's his attitude. In issue #2, he was prattling on to the Phantom Rider about how he was done teaming up with other costumed types. Now he was going to be some major arms dealer, make his cash that way. As if he's the first villain to think of that. As if he's any closer to the A-list than the so-called 'fifth-rate hacks' he used to work with. He really strikes me as the sort of character who thinks he's much better than he really is. Somehow, that leads me to the thought that at some point, he ought to have run afoul of Bullseye, or Deadpool, or Taskmaster, someone who takes a little more pride in their craft, and they'd kill him*.
Hmm, maybe Crossfire is a self-loathing costumed villain? Hates being one, hates being around them, but can't step away from the life? Surely he'd be a less conspicuous arms dealer minus the costume?
* Outlaw shot him in Simone's run on Agent X, but either it wasn't fatal, or it was ignored. That Crossfire seemed to enjoy himself more. He actually had a quickdraw with Outlaw. Perhaps getting shot as a result took the joy out of his work.