I will say this.
Some setups such as GMoney509's Pernicuous Ambiguity
https://epicmafia.com/setup/1174003 are not as scumsided as they appear. This is probably a true 55/56% mafia setup, which is fine. It is a difficult setup, combining multiple lesser used mechanics such as Janitor, Governor, Crier, and Mason mechanics as well as debate over optimal strategy given multiple situations.
The issue is when you need to get 200 plays playing it with people who are normally accustomed to Guns & Hookers, JFK, and FP. In gold hearts, more difficult setups such as these ones are obviously more likely to become more scumsided in percentages than they actually are.
Now the nice thing is that the Round Mod is able to approve any setup for competitive play even if it doesn't have 200 plays to it's name. Therefore this effect is lessened, however when testing a setup it's usually a good idea to have people play it who really know how. Having a custom lobby you can invite people to play it works, but getting people to go there is difficult.
You may have to make a setup more townsided than you would like for it to survive the 200 play barrier, but then when it reaches gold hearts, it runs the risk of becoming far more townsided due to the change in player skill.
I'm going to attempt a balance on Pernicuous Ambiguity shortly and test it with the free time I have today, hopefully.