I try with this
A center needs rebound, ID and IS. He needs these 3 skills to play well, not to be sell well.
A SF needs JS, distance shot, OD, ID, ball possession, passage and to be completed also IS.
If you've 30 points available as sum of potential, you'll have a center lvl 10 in the 3 skills he needs, at the same time the guard will have a lvl 4, let's say also 5, in all the skills he needs. As you can see, a lvl 10 plays quite well, a player with skills lvl 4 no, that's the point. If you try to train a SF in only 3 skills your SF will not play well, I can tell this for sure. I hope to have explained a little bit better my point of view
1990-2022 Stalinorgel - https://www.youtube.com/watch?v=pV-Xppl6h8Et