Relegation

[sparklinginsilence]

I like the idea itself but its not gonna work if implemented like you describe. First as Buffs said,a relegated team will end up being stronger so a team getting relegated several consecutive seasons will be one monster team.
Such a team will not only get promoted but will do so in style,achieving doubles and triples. Suddenly it gets tough for new managers as there are monster bots in the league and they give up on the game.