I mean, at that point you're talking about most heist movies, too. The "defending a community they're outsiders to" mission is so specifically repeated in movies that I think it's inherent to the formula. And that's setting aside that a Dirty Dozen gets pressganged rather than volunteering.
I do think of heist movies - starting with The Asphalt Jungle, if not before - as being in the same family. Maybe 7 Samurai is a combination of the "assembling a team & doing a mission" trope & the "defending a community you're not part of" trope - heists are the former, lone knights do the latter.
& I mentioned The Dirty Dozen being a more conscripted version. Both have "assembling a team for a mission & doing the mission," regardless of whether the assembly is voluntary or what the mission is.