Since I haven’t seen Broman playing, I cannot say much about him specifically. But, if he shoots well enough to be in league with Blake, then we should offer him. At least, he can make a good role player spotting up in a year or so.
However, shooting high percentage at high school level is not a sure bet since shooting percentage is more than a simple mechanical thing. Obviously, he will face better defense from bigger, quicker defenders at the Big Ten level.
At the same time, he will be forced to relearn shot selection. Shot selection in a broader sense is to give your team a best chance to score (with rebounding possibility in consideration) instead of attempting a makeable shot when open as narrowly defined. This is not an easy process to learn since he needs to learn to make quick sound decisions considering a lot of factors on the floor even if he has some tremendous floor reading ability with high basketball intelligence. In other words, he will be forced to do a lot of thinking on the floor, especially in half court situations -- how often have we seen supposedly good freshmen players look dazed and confused with the ball? --, and thinking interferes with shooting mechanic, which lowers shooting percentage and therefore confidence.
It takes a lot of playing minutes to more effectively learn the half court system and shot selection accordingly. But, if he is a defensive liability at the Big Ten level, he may not see enough minutes to “develop”. In that case, he may be better off at a mid-major school where he can play a lot and develop like a certain MN kid that many Holers like to talk about nowadays.
However, Tubby was lenient on shot selection last season because I guess he had no choice with the roster. If Tubby continues to be so, Broman may have a better chance with us. But, I kinda doubt -- hope not -- Tubby being so easy with shot selection.