Wait, if you love Ty's game, then you know his shooting from 15+ ft isn't a big part of it. Instead, it is what Ty does inside that distance (like drive and shoot, drive and dish, shoot or pass over many guards and other players, follow his own shot, otherwise crash the boards, post against other guards who can't handle him close to the rim, etc.).
Notice I never said shooting from 15+ ft but notice that the that stuff I did say can often get a player to the line. Ty can be a great big guard, but he will never be a great shooter from 15+ feet. I do think, slowly, he must improve on that 39% FT shooting from last year. But, honestly, a realistic goal (esp. since he shot 51% as a senior at Thorton) is 50 to 60% from the FT line as a sophomore. In that range on FTs and avoiding 3s (except when the clock is almost out) is the best we can hope for him. (You're right, he didn't do that against Madrid at 1-5 on FTs, but that was one game.)
Underwood is right, Ty's guard play (even with these modest goals on shooting) could be pretty good. Can he magically turn in to a great outside shooter? No. Basically, no one does that. Becoming a great outside shooter is partly genetic. It also normally takes 1-2 decades of dedication and good coaching. There is no way for that stuff like to suddenly change in one summer for anyone including Ty. And considering that Ty is about 20 years old, it's pretty likely he will never be great outside shooter. But he is already a great player. And he can be a very good BT big guard, as long as he keeps working on his weaknesses and plays to his strengths.