Of course than league system should be redesigned to something similar as association model. This would solve a lot of problems. Now you climb ladders with unlimited levels with no benefits or even disadvantages because you lost -20% every time. And vice versa you relegate and your players not lost anything. This is weird thing.
Oh you say when team from championship climb to premier league they look weak but you know there are only few divisions and when you reach highest, you cannot climb more. And there are unlimited divisions/levels. That's why asso model would be way better to make nice structure.
Same should be done with players statistics. Now properly trained player with 5stars can look way better than player with 7 stars.