I tend to think Urban Meyer most likely would have thrived in this environment.

He tended to select schools where the resources were abundant, which would have made quite a few things easy for him in terms of roste building. And as you noted, he was a master poacher, so his tactics not being limited to pre-Signing Day would have expanded his slimy reach.

Other things may have worked against him: Guys he made the bogus promises to wouldn't have been stuck on the roster and limited by the transfer/sit-a-season-out rule....they'd have been able to jump ship right away. This also would have impacted his practice depth, as the non-stars he treated like dirt would never have stuck around. And, the fact that everyone would've been getting paid would've limited his under-the-table deals.

On the balance, I believe he'd have come out ahead and probably been about as successful as he was.