That makes sense to me, and I would assume they would make it that way; however, it has been my experience that it simply isn't that way. In the past, it really just seems that given the combination of their age and potential, they are just going to regress or progress, and that's just the way it is, but I have read that this year their progression will be stunted if they are not performing well, I don't actually know this one first hand, I haven't had much of a chance or desire to play yet (now that OSFM is out though, I'm gonna play a lot). Another thing to consider is what training you have them assigned to as it will give an extra boost to specific stats based on your selection.