If Caponi wants to find players to fit his system, he needs to hit the transfer portal hard this offseason. He doesn't have the time to wait on HS recruits to improve his defense. You can't have the worst defense in the FBS and expect to keep your job more than 2 seasons (or 1 season for many programs).
A couple quotes from Syracuse Head Coach Dino Babers when they switched to the 3-3-5 in 2020.
"In theory, the 3-3-5 is fast, malleable and conducive to an undersized defensive line. If you’re at a place where you have the ability to get a lot of good defensive linemen all the time, you don’t have to go to it,”
The 3-3-5 has worked pretty well for Syracuse since then. As large defensive linemen are at a premium, it would seem to make sense for a school like North Texas to try and switch to a 3-3-5 (at least on paper).