Hi Troy,
When you are redirecting I am assuming they are going directly to the bluecoats. Once you redirect in that scenario you lose the ability to track where they have gone from there since you have no idea what half of the clients are and half the other since they are not being redirected to a load balancer that can track the connections. Unless you can somehow base how you want to half the redirections. For example you want some subnets to go to one pacfile versus another.
Is there any reason why you want half to go to one and the other half to another? Are they the same pacfiles? Are you trying to load balance the pacfiles?
Bhattman