I think Nordeus is just a clueless company, that does everything to hide the game mechanics leading to success to gain more and more revenue.
They have given up on this game, I believe.

Creating mutant players was a legit way for a f2p player to play successfully without spending absurd amounts of tokens. You buy your player for a little amount of tokens, farm your greens and keep this player for multiple seasons and he and your team get better and better, without being matched with high quality teams.
Where does Nordeus get your money then, aye? You must buy their ridiculous 8* recommended player for 1200 token to be successful.

So what does a lazy company like Nordeus do? They change the rules. No more mutant players. People found out too much...

I hate this with this game. You don't know anything. And if you figure something out they change it. They just want you to spend money.