I agree that Tannehill can win a Superbowl but not at his current contract, he's just not good enough to make $38MM per year.
It's fascinating to me, every front office knows the 13.1% rule - Steve Young is the only QB to make more than 13% of the cap of his team and win a Superbowl, I think Farve is next at around 12%; there's a reason Brady won so many Superbowls, he never took his worth (doesn't hurt to have wife that's twice as rich as you). So by paying a guy like Tannehill $38MM you are in fact saying that you think he is the exception, not the rule, he's going to win a Superbowl making nearly 20% of cap when Tom Brady and Peyton Manning and all other QBs never could in the modern salary cap era.
Tannehill is a much much better QB than Teddy Bridgewater (but teams have won the Superbowl with some pretty bad QBs).... now Teddy Bridgewater costs $4MM clearly a downgrade at QB right? But think about these guys: Travis Kelce, Trent Williams, Jalen Ramsey - pretty good players right? all have cap hits less than 10 million per year. That's right, Tannehill gets paid more than all three combined plus a "mediocre" QB.
Now imagine the same exact game against the Bengals last weekend, except the team has the following attack:
1. Running game with Trent Williams blowing people up.
2. Travis Kelce on playaction to throw the ball to.
3. Jalen Ramsey to further shut down the receivers of the bengals.
I realize the above is a PIPE dream, but I'm putting it out there to show people how freaking overpaid guys like Tannehill are. Not that he's bad, but the dude's caphit will, in all likelyhood be higher than Patrick Mahomes for the next TEN YEARS. That's right, Mahomes will almost certainly restructure over and over again to keep his cap hit low enough to chase a superbowl, can I prove it? no, but he's already demonstrated his willingness to do so.
I have no problem with Tannehill going forward - make him take a pay cut - half. He can do with half when Derrick Henry is paid less than that rando RB in Dallas.