Besides, even if he had been adopted and his name was Tom Corleone, would it have made him a better wartime consigliere?
Hmmm...you raise an interesting point. We've often speculated that Tom could never have taken over the family because he was "Irish" (as well as not being a wartime consigliere). But if Vito had adopted him, would he have been more acceptable to the caporegimes and the other families?
Possible. Between the time Sonny dies and Michael returns, I would imagine that Tom was at the height of his power. I would imagine that he ran most of the day to day operateions and spared Vito the trouble of dealing with anything other than "need to know" issues. When Michael returns, we learn that he was groomed by Vito for a year before he proposed to Kay, and
this grooming continued for some time after that. Certainly Tom had the respect of the caporegimes...Tessio even thought Tom might have the power to get him "off the hook" for his treachery.
I would go so far as to say that a big part of the way Michael treated Tom was to "keep him in his place." If he had been an adopted son he might have been next in line to Sonny, and aranoid as Michael could be its possible he saw Tom as some kind of threat to his need for absolute power.
