But, I think Tessio never expected to succeed Vito. He betrayed Michael because he thought Michael was too weak to confront Barzini, who was encroaching on Tess's territories. But, perhaps Barzini promised Tess that he'd be the new Corleone Don after Michael was whacked.
Tessio probably never expected to succeed Vito as Don of the Corleone family same as Clemenza as long as there were Corleone heirs but Vito “once said that the day would come when Tessio and Clemenza could form their own Family†though
Vito always the 'nice' guy fobs off saying “Michael is now head of the Family and if he gives his permission, then you have my blessing†knowing fully well, Michael
cannot give his permission
Michael was the only one who strategiced - Sollozzo killing Vito is the key, the Corleones can't wait - devised the brilliant plan and carried out successfully the murders of Sollozzo and the New York Police captain pretty much single handed
Michael did all that in spite of Tom's “nobody has ever gunned down a New York police captain Never!â€
If that was not proof for Tessio that Michael was “more than qualified to be the new don†confront Barzini, stop Barzini encroaching into Corleone territories
and win
Well, Don Tessio!
