[Belac]

I am fighting a war against Sauro in one game (Mooseknight), and nothing made me happier than when my opponent ran out of money for more hydras. A couple hydras plus high PD plus a few skelspammers was enough to require me to commit whole armies of mine (admittedly, I am agartha and using national units), and combined with any other Sauro force was enough to defeat me as the hydras+skelspam held my forces up while the PD archers slaughtered me.

It stopped working once I was able to get enough elementals+umbrals, but for early research and secondary fronts (send a few hydras on a raid, drop some PD in their province and attack the next--it takes disproportionate force to defeat them, and either you face them+PD or just the PD, which weakens your force for when you do catch up. That's not terribly gold-cheap, but it's cheap on everything else and seriously draws enemy resources away from the battlefront) it was awful.