Signing Tua to another contract to be the starter in 2023 would run a close second to the Fins all time stupid GM decisions (#1 is Culpepper over Brees). Tua is going to miss at least 4-5 games per year due to concussions at the very least . And that doesn't even factor in the degenerative hip condition that was known about before the draft. There is no doubt he's a good guy. So if they want to resign him at the price of a backup QB, that's fine. Get Brady for a short deal to get the most out of Hill and Waddle, and Tua can be the backup in case Brady gets injured.
Another interesting option is Aaron Rodgers. He's guaranteed an insane 60 mil by Green Bay next season, but he doesn't want to be there and they want to move to Jordan Love. They'd probably take a token late draft pick if someone picked up a good chunk of his salary. McDaniels and Rodgers would be quite a HC / QB combo.