the traning facilities in valencia is "need some investment" while i remember in ajax should be "top facilities plus youth acedemy"; but one thing to note is that players in valencia are much more "professional" than ajax.
try the following:
1. do not let assistant man take up the training job.
2. try to recuit better coaches.
3. ...... dun noe le...
btw, based on my own experience, i did not see any major difference in 4 stars and 2 stars.
coz generally speaking, players are able to reach their potential ability (about 95%, and Mutu is always an exception).
but training may got potential impact on players' condition, e.g. match fitness and readiness ( i guess...)
anyway... CM03/04 is about to release next week, and the training system in 03/04 is much more mature than cm4.