@JimMorrison:
Well, I played Gath in ... what did I play Gath in. Methadone. And they didn't eat people. It's your imagination, or you were using some kind of mod that gave LA Kohen Gadols devpop.
And I just tested it, and I can assure you back

, Kohen Gadols do not eat people.
Were you blood hunting with them? That will decrease your population of course.
@Trumanator:
With just 1 attack, F9 is not worth it IMO. You have S3 randoms already, S4 is not going to buy you a lot. You could just go with an E9 Cyclops, and good scales.
For offensive firepower, Flaming Arrows is a good bet, to give you some army power in addition to your thuggery.