I would keep an unhappy Ronaldo rather than swapping him with their useless players
He is professional. If he still with us, it means no clubs willing to pay him and he know it. He will still play at top gear for us like how he scored our dissalowed goal against Udinese last match.
If Man City dont want to pay minimum 30m for him, its their to lose. If the mentioned 150m for Kane is true. If he will get 5 years contract, it means 30m ammortization per year. Yes, you got striker for 5 years, but i think there wont be a club who will pay him to transfer him from Man City which means Kane will play until his retired or contract expired. If Kane flop or dont deliver, he will warm their bench and burden their wage bill for several years. With Ronaldo, they get 1-2 year minimum high performance
With Ronaldo, they got a better player even for now. Better all facets in the game, better mentality, better fitness/injury record. City will have a problem if they can't get Kane. They really need a striker. And if they didnt get Kane, they will have problem to win EPL as Chelsea, Man Utd, Liverpool look strong this season