Originally Posted by
Monstrous Bird of Qin, Ou Ki
As I see it, given that at least two notable Saiyans from Vacado had or were part of mercenary groups...
Callion were more like marauding bandits. They'd find a nice, juicy planet, attack, and then sell it for profit, keeping whatever loot they could get. Maybe they could be directed, but they were almost invariably bad news.
Vacado... some did the whole 'bandit' thing, but a lot of them were probably of a more mercenary bent. Yeah, sometimes/often they'd be hired to do bad shit (hell, Callion probably hired them a lot since they were unlikely to stab them in the back and they'd trust other saiyans to get shit done) but they could also be hired out for neutral or good tasks, too.