So, to put it in the simplest terms possible, you're looking to train a guy who won't be able to score from outside, but makes up for it by not being able to play defense? Having a guy at the point who can't score himself but can set up his teammates is great, but not if he's also a turnstile on the defensive side of the court.
Do yourself a favor and start using the following criteria when you're looking for players (and I encourage it for *all* players, not just trainees or guards) :
OD >= mediocre
HD >= mediocre
PA >= mediocre
ID >= mediocre
Or go down to inept if you really feel like it. And then if you find guys who still have atrocious in relevant skills, ignore them. You'll be able to create much, much better players if you don't start with someone else's piece of crap.