Wait, would Cap even let Deadpool join? Yeah he let Castle be part of the group for a while, but Deadpool is a whole other story.
He won't be happy about it (nor will his player), but player vs player conflict is part of what makes Marvel Heroic better than most other super hero RPGs. Er, I mean the fact that inter-party conflict can occur without ruining the game is.
If Strange is up for grabs, I'd jump on the oppertunity.
If not, I'd roll with Cloak.
I actually JUST ran Strange in my session today (we were short a few players, so I played and another guy was Watcher). It's a fun datafile to run, but it's got some odd SFX and Limits, and really didn't feel as powerful as I feel Strange should be.