I don't discuss this in detail again. I just think it is important to ensure any loan system should avoid one owner use his/her high level team to excessively help his/her low level team, and should avoid any team using loan system to temporarily boost quality of its team (I don't prefer allowing short term loans).

In fact, managers ought not want to loan young players to lower level teams because training progresses of young players will be slowed down. Probably some managers will want to loan players to higher level team so that their players will train faster.