If this is true, is there anything that can be done structurally to mitigate the possibility or the perception of the possibility of hegemonic MN control? I realize that growth over time can take care of the issue, but it seems to be a vulnerability now.
I don't think so, because mn owners are more or less anonymous, i.e. there is no way to automatically determine that mn A and mn B belong to the same owner. So how would you even identify how many mns a particular entity controls?
P.S.: One interesting scenario would be if there ever was a Silk Road-type bust involving Dash, i.e. some law enforcement agency confiscating a large number of coins from a Darknet operator. That would theoretically give them quite a bit of voting power, if they decide to go through the trouble of setting up masternodes