When Mahomes has a bad game, more often than not, he still manages to pull a great play out of nowhere. He doesn't get emotional. He doesn't get down on himself. He doesn't get that dear in the headlights look or, if he does, it doesn't linger too long. If he was playing to Josh's standard against Houston in week five, I think he would have found something to at least take it to OT if not win. The Bills defense had the Texans offense under control for majority of the second half.
That's where he has an edge on Josh. Pointing out the coaching differences and general strength on defense is fair and accurate. But Mahomes re-calibrates quicker when things are going wrong. If Josh played like Mahomes yesterday, would he have mentally pulled himself together to drive the team down the field and get the required points? I'm not so sure. Josh is better than he was, but he isn't quite up to Mahomes' level yet. And I think that's why Mahomes isn't feeling the heat, along with the 6-0 v 5-2 record.