It seems to me like the last mafia you have to beat is always ridiculously overpowered. I threw 200 mobsters at one of their districts and they somehow killed them all... I don't know how hard it would be to implement, but if you could create a system for the mobsters in the game, that simulates new recruits transitioning from recruits to regulars, then to hardened veteran mobsters, by slowly upping how effective they are a defending and attacking that would be awesome... Or you could spend money to train them.
 "Deep State"){kind=icon}
 "NYC Mafiosi"){kind=icon}
 "D-Day Defender"){kind=icon}
 "Record Shop Tycoon 2"){kind=icon}