I thought they were fixed, but then I thought I saw a hydra limping around with one head. I made a disabled (pretty much empty) sacredhydrasfix315.dm just in case I need to apply it in the middle of the game.
Revelers are cheap enough researchers that the ones without blood can sit around in your quarantine lab researching or making snake rings. It's a 20% (1 in 5) chance of BN, so 1 in 10 for B1, not 1 in 20. I'm a big fan of blood, so that's worth it for me.
I've attached my SP save game at around 12 months. Caelum declared war on me, the other nations are leaving me alone. I would not buy this much PD (21 etc) in an MP game, but it keeps the AI off your back.
There was a cluster#!%& in Birman Highs the previous month, where my tower shields managed to get mixed up with my hydras and they all got poisoned and died, that's why my hydras and some new infantry are getting together in Waywoods. They aren't set up to fight yet, but the army in Kolermegor is. This sort of disaster happens about 1 in 15 fights, and it's just a loss of 8 to 12 infantry. Not really a disaster, but it means you have to regroup. I don't like sending in hydras without an arrow shield. I was surprised by a wind mage province early on, but because the arrows were all firing at my tower shields instead of the hydras, I took the province with no lost hydras.
Hydras are terrible at defending if you mix them with PD because you can take 75% losses and route. That's why Kolermegor has no PD.
The map I'm using can be found here:
http://dom3maps.wikidot.com/system
xlands