Terrific summary. Marino had an excellent arm and technique, especially for the midrange throws. He threw a dart over the middle for a touchdown at Shea Stadium as a rookie that astonished Shula and was probably the biggest wow throw of that season.
Tua has a quick release but last year he was hesitant and lacking on those key midrange throws. How he progresses there will dictate the course of his career.
No matter the sport or specialization within that sport the first thing I notice is mechanics. I have no idea what happened with football quarterbacks recently. For all the supposed sophistication in position coaches it shouldn't be possible for so many talented young quarterbacks to have developed such miserable technique, and especially that high elbow chicken wing that is showing up all over the place, regulating Cam Newton and Carson Wentz and Justin Fields, among others. Contrast to decades ago when a shorter less talented guy like Joe Ferguson built a long successful career in the league largely because he had such gorgeous basic footwork and delivery. As soon as I saw Ferguson at Arkansas it was obvious he had NFL throwing motion, far superior -- for example -- to his predecessor at Arkansas, the famed college quarterback Bill Montgomery.
BTW, I have seen some early photos of Wentz with the Colts. It is obvious they are prioritizing his mechanics. Release is relaxed and over the top. We'll see if that translates to live action. There was never anything wrong with Wentz except that incompetent windup he developed.