This does make sense, but I dont realy like it.
Lets say that a SG is capped at 15 in all guard skills and a center at whatever (i have no idea since i dont have this kind of players) for the same potential.
Then for training the optimal player i need to stop training him in outside skills at 14 in one skill and push his inside skills until the centercap hits him.
Ok, this is just an example. I know there are 3 other caps (maybe) that he might hit on his way. And all skills might influence all softcaps, just more or less, so he still hits the SG cap before the center. But the logic still holds that there are a point when you have to change the training, and one training too much might ruin the player ;)
Cap does not work this way -- it's a salary limit, not a skill limit. There is no such thing as a "guard cap" or "center cap" -- there is one cap that can be reached by training different combinations of skills.
You do know that you contradict yourself, right? Since you say its based on salary, there are "5 ways" to calculate salary and the above then stands.
As a whole, your argument is quite confusing.
You talk about "center cap" by which you probably mean "a combination of skills for the center position which will put you over the potential cap". However, the assumption that there are 5 ways to reach the cap is erroneous -- there is an infinite amount of ways to reach the cap, given that even within positions, you can train different skills to get to where you want to go.
Either way, what does "training the optimal player" even means? If I understand your argument, you're trying to train as much skills as you can before capping out. However, if we view a player as having primary position skills, and other skills, it's theoretically always possible to train 1 less level of a primary skill to get extra secondaries, which doesn't necessarily make the player any less perfect.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."