[Agema]

Mm, Vestals are definitely worth it if you've taken a good combat bless, although I expect if that's been done it's because the player is eyeing up the bless for the sacred angelic summons.

Yeah, I've done without hydras. You get over 20 velites/alaes/hastatii (or 16 principes) per hydra in gold. Instead of 5 hydra, buy 50-60 alae and you'll have about 600-700 gold left over to put towards a new castle, better mages or whatever, and you'll still be able to smash independents. Although you probably won't have enough res to buy that many units until you've conquered a few provinces around the capital.