To prevent the current manipulations the FAs need a reputation based system like the Friends Leagues have.

It could give equal opponents if the margins of reputation points is set based in the AvQ of the 4 best teams and then assigning +/- points to be assigned in case that a team is, for example 2* less/+ than the average, or something similar to create a fair ambient. But it needs to be based in rewarding the teams for playing vs similar teams in terms of quality, this should be a priority.