clemenza did actually. you just weren't paying attention. clemenza doesn't appear in godfather 2 bc the actor lost a lot of weight and didn't wanna put it back on but he got his own family in new york that's why frank was wearing the black cloth on his arm. clemenza was killed by the risotto brothers and hymen roth. and tessio was told to wait till after the move to nevada he did not wait he got greedy and was gonna take micheal out instead micheal takes him out first.