If you look at it from another angle. If you dont have trainees you wont need to waste money on a trainer and can expand your arena and/or buy some better players that will help you reach success faster.
If you only look at the starting roster and training potential sure things can be unfair. But who says you need to train players right away to be successful?
Or another view from the same angle:
If you're the type of manager that thinks that the starting difference of a few hundred thousand because of a lucky trainee is going to be the difference between your success and your failure, you're wrong - not about your eventual failure, however, just on where to point the blame.