Not even close to the Chicago Outfit in terms of ruthlessness. The bootlegging days were wild in Detroit, but the Tocco-Zerilli mafia from which spawned the Partnership always seemed to be a low-key family that prioritized keeping close family ties in the organization to keep the stability and made sure that the members of the family got educated. Gambling and loan-sharking were always their main blue collar rackets and they seem to be very savvy in white collar crime and infiltrating the corporate world. They immediately realized it's pointless to hold on to their former territories and go to war with African American gangs, Assyrian/Chaldean mobsters and bikers when Italian Americans weren't a factor in those communities anymore. A very quiet family, which in a way contradicts with the ridiculously violent reputation the city of Detroit has.

The Chicago Outfit on the other hand had an almost unparalleled bloodlust in their prime. There are reports of debtors getting maimed in horror movie like ways and despite the fact that the Outfit was famed for having high-ranking associates, being an associate of that organization could also be the very worst place you could ever find yourself in. When shit hit the fan, even if you were very well liked, they were gonna whack you. One botched job could be enough for them to pop you. Extremely ruthless organization in their prime and I'd go as far as saying that the level of violence they were willing to get into was never gonna be sustainable in the long run.