They are both merc companies, and both describe themselves so.
REILLY REILLY REILLY!
I just love Brick XD
I wouldn't really call the Rangers a company -- more of an elite band. And they call themselves mercs, but really they specialize in mapping and exploring.
So, really, you can't really compare them, but I'd say Reilly's group are actually better fighters but there's only like, what, five of them? That's including the Lone Wanderer if he joins up. I'm amazed they've done so well with those numbers, to be honest.
And sorry, but I HATE Brick. She just really, really annoys me. It's either the voice, or the fact I hate women like that who act all tough. I'm not being sixist, as some of the more solid women -- Sydney, Sarah Lyons -- are okay in my book... but Brick. Hate.