Instead of (or in addition to) reducing numbers of votes, I think we should also increase the number of witnesses that participate in the consensus rounds, maybe to 40 or even 100. This whole mess was created because 20 witnesses were able to collude and do a ninja fork that locked the disputed stake. Reducing numbers of votes won't change that.
Despite the claim that their fork was "reversible", reversible doesn't necessarily mean temporary. Based on the prior and subsequent behavior of some of these witnesses, I'm not convinced that Tron would have ever seen that stake again without somehow installing their own slate of witnesses. It only would have taken 4 witnesses to keep it locked in perpetuity.
IMO, the "offsetting penalties" by both of the hostile factions demonstrates a clear need for a larger number of witnesses to be engaged in the decision-making positions.
Actually, I think that is an even better solution! That would definitely avoid the concentration of power... But would it have problems with the lower thresholds?
Of course that means each witness gets less as they verify fewer blocks... But we will see who puts the chain first.