It’s not convenient for the wolves. A balanced town is a happy town. Because as long as they stay balanced, they can keep hunting wolves only. Your statement that it would be useful for the wolves to have a way to determine alignment to better divide the town is spot-on. However, you are saying it for the wrong reasons. Wolves don’t want to keep the game balanced. If one side of town gets too powerful, the other side will need to take out the more powerful side or lose.
Of course, it is possible that the wolves not only have farmers and ranchers, but themselves are divided against each other, so we essentially have a four faction game, in which case you simply want to decimate a faction just to simplify the game. But don’t eliminate a faction, because then you rebalance the game. You want a faction with only one or two players. Enough that they can provide a distraction, but not enough so that they are a true threat.
Keeping your opponents balanced is bad, because any losing faction that wants to still win will ally with another losing faction to take out the stronger one.