You'd like to think Ronaldo is a slightly more humble and maturer person than the one of 10 years ago, realising this is his last chance of going out in a blaze of glory as it were, so he would fully buy into the Pep aesthetic of working hard as a team, he would also know from discussions with Dias, Cancelo, and Bernado what he's like as a man, and a manager, I'm sure there would be a high level of respect for each other's achievements.
Forget his history with UTD, if he can do a job for us for even just a year and come away with some decent silverware, then I don't have any issue with him playing for City.