thx for your comment!
but what do mean with "expand from there after they start to improve"?
You might not be able to find a player who is (1) good enough to start at SG in the 1st division; (2) be young enough and have enough potential to be trained; and (3) affordable.
You said that you have the starting PG who meets these criteria (he already starts for you, he is 20, and you already own him). Your second PG doesn't have to be able to start for you.
After you have trained a while, your 2nd PG will be able to start in league games, so he can split the starts with your 1st PG. And then you can train a 3rd PG in scrimmages. Or you can switch one of your PG over to SG (passing won't hurt him). At that point you might be able to switch over to trainingSG/PG training.
So you can initially start out with fewer players, who will train faster, while not making you vulnerable in league games.
If you were to start out trying to train 6 players who play 48 minutes each, you will need 4 players who are starter quality.