Note that this is effectively White Flag: if there's only one scum left then they instantly lose if it's ever 2:1 and have no way to win from 3:1, so a 1 scum ending will inevitably lead to a town win eventually.
The numerical dynamics are weird, though; I don't think I've ever seen a setup before where 13:4 is 50% town EV, but 11:4 is "town are on the verge of instant loss and need to play perfectly from now on".
I therefore have a suspicion that this is somewhat scumsided in practice, even if it's balanced by EV. Normally the downside for scum for manipulating a Day vote is that it becomes obvious you did it, and obvious you had scum motivation behind it, in retrospect. In this setup, scum have the choice of aiming for 0/3 or 2/3, so it's going to be much harder for town to figure out what scum are doing (or even know what scum would be aiming for).