Those players were good evaluations and thrived going from Donofrios scheme to Diazs first year 4-3 scheme.
Diazs true scheme (4-2-5) has been completely scouted and proven to be fundamentally flawed.
Diaz also hasn't recruited or evaluated well. He has a roster full of under-performing defensive backs, and small under-performing linebackers who get labelled as strikers as an excuse for being unable to play their position.
Its not a coincidence that his best players are transfers.
Hopefully there's some true talent in the recent classes, but will we see them? Diaz prioritizes seniority over ability.
Diaz never played the game and he's trying to teach things now. That's why we see the gimmicks. Its a crutch to make up for lack of knowledge. They teach the "Hawk" rugby tackling which is why they don't tackle well, and bounced off Bama.
He brings in his "Nascar" package on third down which is easy to audible against.
He has "strikers" which again are just players who don't play any one position well enough.
He has defensive backs playing off while blitzing leading to open hot routes/quick throws.
He doesn't disguise or feint blitzes.
He created the chain and rings.
He has analysts measure the "spontaneous positive reaction to teammate success" resulting in players dancing on the sidelines in an Orwellian attempt to appease big brother into more playing time.
Everything's a gimmick because he doesn't know how to actually coach.
He has peaked in his career and when he finally does leave, it will be a fast, graceful exit to take a demotion to a job with no expectations.