Setup ISA server array

Hello, we have one production ISA server which I would like to set up in an array with another virtual ISA server in the same domain, but different subnet. As a test, I copied the current configuration from the production ISA server to the virtual. Would setting up the array impact the current active ISA server? Would being in an array serve as failover and load balancing? I have read a lot about this set up, but I would appreciate any input if anybody has had any experience setting this up, thank you.