If you look at when he was actually there, and you look at the improvement from before he got there, that's worth noting. Not to mention it's tough to make a big impact at all in one year, but he's done it at most places regardless.
You're also not considering personnel. USU had a massive senior exodus and then he came in. I think they lost all 5 seniors. Love was a bigger problem than anything in 2019.
This last season I don't really care to judge anyone. Gary was a mess and his program was a mess.
But things have improved under him for the most part where he's been. And he'll have way more talent to work with. Outside of circumstances beyond his control like personnel when arriving, age of players, etc, he's proven success. OL are hard to judge, but run game, sacks, e.t.c, they at least give some insight.