I don't know how long it's been since I've seen a horde victory in Isle of Conquest.
I could maybe "get" that the more traditional battlegrounds, like Warsong Gulch, Arathi Basin, Eye of the Storm, and so forth have more or less "even" win ratios, but... frankly, I wouldn't believe that about Isle of Conquest or Alterac Valley. And if they DO have "Even win ratios," either the horde on my battlegroup are unnaturally terrible at them, or I'm just a really good leader who people listen to.