In order to hire specialists for better training of your players, you have to calculate salaries and both signing bonuses. That's ok. But what bothers me is that you need to have 10 times more money that your actual cost for specialists is. Currently I have roughly 70k profit each week, that could be invested in staff week salary (instead for buying players for example). From the other side, I almost can't afford to hire any since I currently have no money to cover 10 times their (for example) 20k salary plus bonuses.
Once I gather that much money to hire some number of staff, I'll have to gather new , even higher bunch of money to get more stuff. In any case, I'd have enough money to cover salaries and rest of expenditures... So, training improvements are very hard.
Not to mention that this fact is not mentioned in rules (which would probably made my money investment some other way), and that there is not some guideline in creating players. How to train my players, when not knowing what to train, while not having who to train with...?

It's not problem in long term planning, but in a way that could be veeeery long term in order to become just a bit better. The improvement seems to be very slow.