A system can be unbalanced if it has an effect that I call counter-balancing.

Basically, as the Side grows, it becomes less and less able to defend itself against smaller opponents. Essentially, it suffers from the Law of Diminishing returns, and winds up growing pas tthe point where another addition adds no value to additional units decreasing Side effectiveness. It basically grows itself to death.

Given that Erfworld has never been "won", that no empire has ever conquered the world, something needs to be ensuring that it can't happen. Even if one side may have a unit that dominates others, unbalancing it allowing the side to quickly conquer and grow, it hits a point where further expansion will cause its own downfall.

If this is so, then Parson will have a big problem later. He'll need to find a way to break the impasse that prevents final victory..