100 Zombies vs 3 Gorillas

Who would win in a fight? 100 zombies (Left 4 Dead zombies) or 3 gorillas decked out in steel armor given only a hammer and their hands (As well as whatever else they can use)

All zombies come at once, and the three gorillas can start wherever as close as they want together. This entire thing takes place in a big park so the gorillas cannot be cornered. I personally think the gorillas have the upper hand here.

Edit:It is now 5 gorillas.