I don't have an opinion on the numbers, but the voting system in general:
The placeholder numbers are:
- a minimum of 20% of Stack Exchange network moderators must vote on if a violation was committed
- a minimum of 90% of moderators voting must vote that a violation was committed
At the time of writing, there are 541 network moderators. These percentages would require there to be a minimum of 108 moderators voting, with at least 97 of those agreeing that a violation took place. These percentages may be adjusted during the feedback and review period for changes to the Moderator Agreement.
I'd recommend to not have a "minimum participation" clause, but instead a "minimum agreement" clause.
As is, there is a possibility for a situation that a moderator not agreeing finds it more favorable to abstain instead of voting against it.
E.g. when 100 moderators already said "yes" and 7 "no", one additional "no" vote will move the result from "no" to "yes".
You normally don't want such negative vote weights in your voting system. (With secret votes, every single no-leaning moderator would have to guess how everyone else voted to decide whether it makes sense to abstain or vote no.)
Instead I suggest something like this (feel free to adjust the numbers, this was just to keep it somewhat equivalent):
- A minimum of 18% of the Stack Exchange network moderators must vote that the violation was committed.
- A mimimum of 90% of all moderators voting must vote that the violation was committed.
This means at least 97 moderators (with the quoted numbers) need to agree that a violation took place, and not more than 10% of all voters disagreed.