If you do the math on Carney it makes no sense for him to take on the leadership of the Liberal party.
He would be leading a party in shambles that is destined to be crushed in the next election. Carney will be 60 at that the time of the next election. So even if he rebuilds the Liberal party and wins in 2030, he will be prime minister until he is 70. Why would he want to do that? He's also straight out of the mold of the '2010s globalist leaders' that are being ushered out of power seemingly everywhere in the western world.
My guess is he's be finance minister until the election and then, for personal reasons, he'll move to a private life of sitting on boards making a lot of money.