When I read book four and five, I get the feeling that there was a reason for the elves to begin the war, and not just because of the power the Voice has over the Elf King and other individuals.
Maybe there was a bit of racism on the humans part, as it was hinted when Enzo was hoping for a better life in Cielis, but feels that no matter what, as long as others looked different to the humans, things would never get better. At least that's one theory, that many humans looked down upon those cursed with animal forms and the elves.
Another thing to back this up is for the lack of animal stonekeepers and very few elf ones, most of them being human. Why? Because the Mother Stone was mostly in the Council's possession, giving them the right to decide what happens to it and possibly who gets a bit of it's power to become a stonekeeper.
Maybe I'm thinking too much on this, but it does give you something to ponder on to what helped push many elves into agreeing to go to war, even if it was their king's orders. Maybe some are sick of how they have lived, as a glimpse of the first few pages of book 2 show that some parts of Gulfen, at least around the palace, appears to be barren.
I'd like to hear what others think too on this. It is something that's been bugging me for awhile.