Bonavena looked crude against boxers but he did show some skills against Frazier, Chuvalo and other pressure fighters.
I guess a comparison with Fullmer can be made, in that he would try to do his best to spoil and brawl against good boxers, while trying to outbox and counter punch the brawlers.
As tough as Bonavena was, I'd rather see him fight Shavers like he fought Chuvalo and not like he fought Frazier. Shavers destroyed everyone whom he was able to get against the ropes. His looping right to the body usually set everything up.