"When Eblouissante bounces out of the gate, she is in the individual dynamic zone. She is immediately looking for another horse to match rhythm with. This is in contrast to Zenyatta, who would break out of the gate in the group dynamic zone and immediately start sizing up the entire herd of motion."
While I think that there's probably some truth to horses wanting to herd or not, this all smells a little like seeing what you want to see.
Still, an interesting read and something to think about...
http://cs.bloodhorse.com/blogs/unlocking-winners-handicapping/archive/2013/01/18/looking-at-eblouissante-through-herd-dynamics-and-emotional-conformation.aspx