Game managers. I have a slight problem with that term. Considering the chiefs have compiled about the 3rd best record in the entire NFL since he has been there over the last 4 years now, I'd say he's done a hell of a job "managing games." His ability to not make many mistakes and execute critical plays every now and again have been crucial to the Chiefs success.
Mahomes may be the long-term answer; however, the Chiefs play in arguably the best division in the NFL with a loaded Raiders team, a stout Denver D, and a talented (though underperforming) Chargers team. To assume Mahomes can walk in there and go 12-4 or 11-5 (which the Chiefs have done in 3 out of 4 seasons Alex has been there), in that stacked division is nonsense.
Chiefs fans seem to quickly forget how they were 2-14 the year before Alex Smith and Andy Reid got there. They have been a machine ever since.
There's no reason to press the issue with Mahomes right now.