Yes, Kill Points is severely limiting to many armies. When playing Imperial Guard, for instance, things get terribly difficult to balance. Indeed, almost impossible unless you happen to be running a Grenadier army and even that isn't ideal.
Marines: 1 troop choice, 200 points: 1kp
Guard: 1 troop choice, 200 points, 4kp
The biggest problem is that there's no way to get around it. If you roll a KP based mission, you lose, almost guaranteed. If you roll an objective mission, you have a distinct advantage, but most well-balanced armies still have a chance. I mean, the most standard way for a Guard player to fill out his compulsary slots:
HQ command Squad
Platoon (1 hq, 2 squads)
Armored Fist (1 squad, 1 chimera)
Thanks to the way Kill points are set up, each of those command squads is worth 2kp. So, to fill their compulsary slots without going doctrined, a Guard army has to take a whopping 8 Kill points. Anyone else has three.
If I play Guard, I'm using Lonewolf's balanced KP method. Otherwise it becomes effectively impossible to win. Any suggestions to rebalance Objective missions to balance this out?