I think Jake Fromm is the guy they'll like, he seems like more of a fit for what they'll probably want. I think a guy like Grier values proposed "fit" over upside and talent.
Tua has operated primarily an RPO offense during his only season as a starter. However, Mike Locksley has moved on to be head coach at Maryland. Steve Sarkisian is Tua's new OC, and he's installing more of a progression based offense. You'll still see Tua operate the RPO's at a masterful level - but with more progression based reads and post snap verification.
Herbert operates mostly out of the pistol. Trevor is a 2021 prospect.
None of these guys are going to come in and run a Tom Brady offense day 1. You have to keep in mind college players are only allowed to practice 20 hours a week, so you can only get so involved in terms of intricacies. They don't have all day to practice like NFL players do.