Configuring windows cluster clients for backups

Hello.

I'm wanting to confirm and make sure we're configuring windows clustered clients in Netbackup correctly for LAN and SAN clients.

Today, we're creating two policies. One policy for the two physical servers and one policy for the VIP. I have others saying that we should be using nbemmcmd to create an app cluster and to populate /usr/openv/netbackup/db/altnames so, that any member of the cluster can see the backups for restore purposes?

Is it neccesary to use nbemmcmd? If so, for what and why? Thanks!

Example cluster:

Physical server A - C:\, D:\ and System State

Physical server B - C:\, D:\ and System State

VIP  - E:\, F:\ and G:\