Jalen can do fine.
Tua is a special talent.
Tua will need to prove he can eliminate mistakes to take #1.
Jalen was 17 TDs and 1 INT, and guided the team to the National Championship as a true freshman and 2nd year. Can Tua have the consistency to do that, that had not been proven game in and game out. There will be a rotation until the first tough, tight game. Jalen starts, but lots of Tua. Barring injuries, of course. Tua needs to prove the consistency. One/Two inconsistent games, could cost season at QB.
Tua proved himself all year long, every chance he got, and had only 2 turnovers the whole year. Since you included Jalen's freshman year, I'd note that he turned over the ball 14 times that year, and fumbled several others that we were lucky enough to recover. He also quarterbacked an offense in the title game, loaded with elite players, that had only 2 series more than 5 plays. We went 3 and out so many times that the defense had to defend 99 plays vs a good offense. That'll get you beat and it did. Going 3 and out is a lot like a turnover.
Some folks claimed during the year that Tua hadn't proven himself under pressure. Coming in the 2nd half of a national title game, after the offense hadn't scored a single point and couldn't move the ball, was pressure, and he won for us the national title.
As for consistency, I've watched every game the last 2 years and have seen Hurts consistently struggle against good defenses and Tua play consistently well when given the chance.
Tua has 77 pass attempts, with 11 tds, and 2 turnovers. Hurts has thrown the ball 255 times with 17 tds and 1 turnover. Extrapolate Tua's attempts to Jalen's numbers, which is about 3.3 times as many, and his tds would be about 36 and turnovers would be about 6. Heck, round it up to 7. That's a sight better than we've been getting.
I'm not sure where the idea comes from that Tua is really bad about turning over the ball, but the stats prove it isn't really so. For those that might say it was from practices, I'd ask what is more important: practice, or real live games?