No spears?
As far as I know from bible lessons, spears were used (IIRC the Akravaim from "Avi yser etchem beshotim veani ayaser etchem beakravim" were spearlike)
And Ya'akov grabbed the ankle of Esav when they exited their mother's womb.
As for the tribes, in the bible the different tribes didn't have much of a different identity to emphasize in the game, so I don't see how you can add them (except for maybe the Levi).
Maybe they are mentioned in other sources, but I wouldn't know about that.
And cavalry is an option, IIRC king David had many horses at his disposal. (Though I agree cavalry should be weak, if at all existing, since in most of he stories the Israelites had very little cavalry/horses, and Israel does not have any natural population of horses AFAIK)
BTW, the ancient israelites had the technology to build siege towers, so if you feel like giving them some sort of siege weapon
EDIT: Whoops! Apparently the forum software can't support hebrew. *replaces hebrew with "English"*