I don't have data on wingmen for outisde shooting but I have some data on Jump Shot training...
So this friday I had little surprise - my 18y trainee has improved JS second time in row. And actually it was his 3rd pomp in 4 weeks of training... I can imagine that he was very close before first pomp in 1st week but anyway, it suggest that it is possible that he gets JS, in the worst case, every 2 weeks. I see the explanation in that he is young, of course ;), and maybe that he has JR higher (now just 1 level but at the begining it was almost 4- he improved in JR also in 1st week), but on the other hand it is training for 2 positions - Wingmen...