I couldn't agree more. I think it would be awesome if in the grand battles your class actually mattered. Titans on the wall stopping invaders, warlocks in the city fighting the hord that has tunnels underneath, hunters fighting through caves to assassinate the enemies general at the rear of the forces. If any faction finishes early they're naturally pushed into helping the others. Titans helping take out the general, warlocks helping the Titans on the wall, the hunters fighting from the rear to reach the cities wall.