In a mafia game, even numbers means the bad guys have already won. Most werewolves games immediately end when the numbers are even.
In a 12 player game, I'd say no more and 2 assassins, especially if those two roles are going to be a role that can recruit AND a role that gets 2 extra kills. If the marksman used his ability the first night, that's 2 kills right away, 5 assassins would already match the town and win.
Or maybe I should hit refresh before responding in a tab I've had open for 2 days. Sorry, busy week.