I think it's easy to get sucked into continuously trying to upgrade your trainees. I have 3 excellent trainees with whom I'm very happy. However, I can't help but think that if I had held onto the two guys that I drafted two seasons ago in my first draft, my team would be further ahead. Instead of being in Div IV and looking to get back to III (unless my competition gets alot better, really fast, I should be able to make it), I would probably be a strong Div III team with those two guys as my center-pieces.
Both were 19 y/o when I drafted them, so that was the essence of my logic for getting rid of them.