What rules changes would you propose? I've noticed the following problems:
1. Circumventing the CR caps by buying numerous extremely low-CR creatures (like hundreds of rats) for nearly no points. Most of them aren't so much part of the army as a group that sits around "supporting" the leaders.
2. The map is too big. Armies will never meet on an open field if they can never find each other. =]
3. Low- or non-intelligent troops acting autonomously. The weakness of dumb things is that they have no grasp of tactics, mostly can't communicate, and in the worst case, can't tell friend from foe.
4. Custom monsters getting out of hand. For one, there are just too many of them, but they are also far more optimized than most core monsters/characters.