Not quite sure what you mean about "backup". Isn't this one of the super-mutant missions? What's the goal? Anyway, I'm on mission 14 or 15 now, and I don't recall any missions giving you "backup" of any sort. One thing to consider is that the patch (whenever it comes out) is supposed to fix the recruit pool problems. The bugs with the pool are the reason I'm still using a bunch of initiates, with the exception of Stein. (I ditched Kevin and took Stein.) Anyway, I have Farsight (Str 4 I think?), Stitch (Str 6, but Per 4), Jo (Str 6 or 7), Trevor (Str 8 or 9) and Steing (Str 6). Not sure whom you took with you, but if you want to switch to different recruits, wait for the patch. Now that I have PA, all of my characters have at least 6 Str, so they can all use any weapon up to the Laser and Plasma rifles.