Mahomes has started a total of five games, way too premature to even consider him in a class with the other QBs mentioned.
I rated Mahomes the best QB in that draft after watching him work the grease board with Jon Gruden in one of those pre-draft shows where Gruden would walk a group of QBs through the paces.
Mahomes ability to process, and process fast, was evident. He even talks fast. He says he hasn't had to adjust to the speed of the NFL game. I believe that; he looked like he was already processing at NFL speed.
Arm strength and quick release are important, which he has, but the ability to process the field quickly is what a lot of big armed QBs lack. Romo, a guy who's especially articulate in describing what goes on, has called it "processing spacial relations".
To your point, Mahomes may be experiencing a "triumph of the uncluttered mind." (See Blain Nye, Cliff Longley, Thanksgiving Day, 1974
). We still need to see how he handles the growing attention, the outside distractions that come with it, the rising expectations, and the backlash and nay-saying that will follow the inevitable first stumble and then the inevitable ones after that. He has some potent weapons at his disposal. How will he adapt to their injuries or his own? How will he adjust to the inevitable defensive adjustments as he puts up more tape?
Though Prescott's debut was not so gaudy, it's an instructive example. Whether his fall off from the "next elite" is a function of pressure, defensive adaptation, failure to counter-adapt, fall-off in surrounding talent, coaching failing to adapt, or a combination of factors leading to a "cluttered mind", an early hot hand will eventually be tested. Will he be able to say, "relax", when things go awry and then back it up?
We're a decade into a P. Manning-Brady-Rodgers-Brees elite that nobody has been able to crack. Or the decade-long second tier of Ryan-Roethlisberger-Rivers-Stafford who have had their own ups and downs but with an impressive body of work?
Whether Mahomes or Goff or Wentz, those varying degrees of uncluttered minds could take their team a long way in one season. Stacking success over multiple years is a matter that remains to be seen. There is a consistent and intense focus and mental toughness and resiliance that is required for prolonged success.
Many have been called; few have been chosen.