Washington can shoot. He'll probably have the best percentage next to Battle, but minutes/attempts will be the question.
Howard will shoot when open and has shown he can hit 3's once in a while. He'll probably be a subpar 3 point shooter around 30% from deep. Good enough that opponents have to respect him after he hits a couple but not good enough that they'll gameplan for it.
Moyer and/or Brissett will probably both be in the high 20% range from deep on limited attempts. Not good, but not atrocious. People act like neither has any kind of jumper but both were able to step behind the arc in AAU/high school every now and then with a little success, so they're not hopeless. Moyer has more potential than Brissett to surprise. For instance, I wouldn't be shocked if Moyer got his 3 point percentage into the low 30's.
I think TT will be the big surprise. Nobody thought CJ Fair had a 3 point jumper when he got here. He was a tall, athletic forward who played well near the rim as a Freshman and people thought that's what he would remain. He ended up being a legitimate 3 point threat after working on it for a year or two. TT has already shown that he has confidence in his shot. If he gets the OK from JB to shoot, he might give us some 3 point production we didn't count on.
So I think we're looking at 2 real shooters who could finish the season at 35%+ from deep. Then we have about 3 guys who will be around 30% from behind the arc. Needless to say, 3 point shooting will not be a big part of the offense. The good news, though, is that 3 point shooting isn't required in order to field a good basketball team nowadays.