Brother, I respect your opinion very much.
But Brady cannot be the rule, because he is an extreme exception. If we go read the names of EVERY 6th round draft pick since then and see how many were successful, we will see a lot of guys, both athletic and not athletic, who were not successful. Yes, the entire NFL made a colossal mistake missing on Brady.
When we look a Brees' limitations, that can be translated into one thing--his height. He had a strong arm ... Tua does not. At this point of his career, Brees no longer has a cannon, but when drafted Brees had a strong arm and threw with good velocity. He was injured and that really threw a monkey wrench into his career, but yes, he was recruited/drafted over when the Chargers selected Rivers ... but Rivers didn't turn out to be a bad QB either. The biggest difference between the two may actually have been Sean Payton, who is a genius and built a team around Brees allowing him to reach his very high potential. Brees was a very good prospect ... just not very tall.
IMHO, the hype for Tua was far too high, and if he had been the QB for Kentucky, nobody would have wanted him in the top 5. But at Alabama, they didn't have a history of good QB's under Saban, but the rest of the team is stacked with talent behind talent. When you sit behind a line of 5 guys and most of them play in the NFL, you're very fortunate. When you pass to 4 WR's who are all 1st round NFL draft picks ... that's an unbelievably talented stable of receivers. When you always have the option to hand off or pass to a Najee Harris ... that's an offense that is far more dominant than an NFL team can sustain and rarely--if ever--achieve vs. other NFL competition. The salary cap simply will not allow that level of dominance, because there is no recruiting really, it's almost all a combo of drafting and salary cap management creating a great level of parity. So, we didn't see an accurate picture of what Tua will face in the NFL. As I've said many times, many QB's struggle adjusting to the "NFL open" window, and the most famous explanation comes from Peyton Manning, because as a rookie his coaches kept telling him to pull the trigger and he kept saying the receiver was not open and his coach kept saying "in the NFL, that is as open as people get!" It didn't come in his rookie year, but Manning obviously adjusted, and I think Tua will too ... but he's not there yet.
If I were making the decision on draft day, I would have drafted Herbert, and I'm on record saying that. If I were offered a swap of Herbert for Tua today, I'd take it. But that's not what happened nor is a swap ever going to be on the table, so the only options are to build around Tua (a very good option), trading for Deshaun Watson (a costly and risky option with a high upside), draft Zack Wilson or Justin Fields (arguably higher ceilings than Tua, but also riskier), or mortgate the future and throw a bazillion picks at the Jags to tempt them to trade you the #1 overall pick and steal Trevor Lawrence (neither the Jags or Dolphins are interested in this option). Looking at all of these options, building around Tua is 90% likely (pure speculation on my part) to be the option ... and it's a very good option.
Neither of us really has a say in what the Dolphins do (I'm assuming you do not, and I KNOW I do not), and whatever they decide we will still be a promising team. So cheers, whatever our beloved Dolphins decide to do, we will support them and look into the bright future together.