Let's look at potential paths. There are 4 knowns. That leaves 5 unknowns. One is the gunner, who can randomly shoot any of the 4 remaining unknowns.
Gunner blasts away. If they get the fool, great. Lynch all other unknowns and end the game. If they get the wolf shaman, don't vote and re-check everyone with perfect information. End game the next day. If they shoot the wolf berserk, same thing since the shaman can't be used when solo. Only if they manage to 1/4 the one remaining villager might they have an issue, and only if that villager doesn't have an ability (like loudmouth or avenger) that can reveal/take out another player.
But let's say that happens. The wolves have to kill the gunner that night, anything else leads to a guaranteed loss (gunner shoots a wolf or fool the next day and village lynches the remaining / checks the remaining with no shaman). Let's say the berserk goes awesome and a witch dies.
Now there is the detective, aura, wolf shaman, wolf berserk, fool, remaining witch. At this point the fool must extend the game by voting with the wolves and the game is probably lost for the town unless the fool is generous in a 1v1v1. To avoid that, the village should probably actually leave the gunner unprotected to maintain numbers. Doubt they come up with that though.
All that being said I give the evils maybe a 5% chance of scraping through.