Your proposal was good if the leagues of the same level were similar in terms of team power, but we all now this is completely wrong. I'm plenty of examples where team 4th in a league are much worst than the ones that won other leagues of the same level...
..in fact my advise in order to win without big amount of token consumption is not to be very strong, but to find the right equilibrium...and to be not too much strong! I can clarify if it may interest!