Any criminal group is going to need a leader, aka captain, to function as a cohesive unit rather than just a bunch of thugs willing to backstab each other to get ahead. Someone needs the last say on what the plan is and how things are handled. There's a reason such a position evolved.

Any skilled crew that can elude capture for so long would need a good captain to lead the path.

Anyway, what did you have in mind for alien species / general tech level? Obviously sci-fi, but how sci-fi? We talking like Halo humanity stuff where it's near future (i.e. still projectile weapons) but we still have interstellar space flight, or crazy far future with light bridges and ubiquitous energy weapons and the like?

I have an idea for a mechanic type character that could be fun, if a bit unwieldy.