So... it's just the Mexican drug cartels and the Italian Mafia in an arena type setting?
I would guess the Mexican drug cartels are far better armed.
Now, put them in the same city, or try and invade each others territory and things open up more for the Italian Mafia since they seem to work a lot better with the authorities and are better at logistics and organization.
Well... assuming by Mafia you mean ALL of the sothern Italian crime families, and not just the actual mafia which only has to do with Sicily.
Straight firepower and Brutality the mafia doesn't stand a chance, give them the ability to bribe officials, get law enforcement to crack down on certain areas, portect and blackmail people, get extra money from running rackets better and more efficently... the Mafia have a good chance.
Coincidentally, the Mexican drug cartels and Mafia apparently work together to move drugs like Cocaine into Europe.
