it also matters what job you're doing and what you have for a crew

like you don't just up and play rats, watchdogs or firestarter on overkill unless everyone in your crew is repped to at least 50 because there is no stealthing the first day, a fight is guaranteed

but you can theoretically run jewelry store on overkill very very early on, provided there's at least one ghost with ECM and one mastermind who can dominate a guard, because the whole point of that job is crowd control and speed