My main team have 7 players in scout level and 1 7*, i assign my SP and i still didnt promote the last 2 seasons, and this season i am current 7th place, i also didnt use any ilegal formation.

So i can say not promoting is not hard even with autoassignement, whend you get around lv16 or above.

But this isent the big question, without the possibility of training properly, one of the fun things in the game is lost.