The dreadknight's chaos is just too good. Teaming a dreadknight up with a paladin can create a super stack in the early game that easily destroys 8 stacks behind walls with few (if any) losses.
Seems to me that all heroes should have command as a base ability. Perhaps they could purchase a limited amount of chaos (or fear) at higher levels. However, they really shouldn't have basic abilities that stack with other hero's basic abilities.