If you've got your army and they're that good why waste troops doing the shit jobs. Supply train guarding, garrisoning some shithole as your troops move through to continue the war. Sure we're not going to be paid to do [i]nothing[/i] but getting paid to do shit tasks and maybe fight (but surrounded by a larger host) is better than putting your life on the line when you're outnumbered. I'm sure we're not the only mercenary band and we've got a reputation that goes back long way. Sure we hire brigands and such but who doesn't. 

And I mean... who wouldn't send us on the worst and most dangerous missions. Mercenaries right? I'd feel safer being part of a larger army than a smaller one. 

Besides - Taratis for Taratio.