I have trained two perennial allstars to their cap before and I can say, that they are quite even.
My SG's skill set is very similar and both have the same amount of skill-points withing the 6 guard-skills. Yours is better at passing but weaker at JR. The inside skills are about the same too.
I would recommend to train him until off-season and see if he still improves somewhere. If you get yourself a decent trainee, don't bother to train him any longer.