GTM irule pool select

I need to load balance to VIPs and generic servers across three different pools. Need to know if this will work?

Pool one contains 2 VIPs the that reside on an integrated LTM.

Pools two and three contains a pair of servers added to the GTM as generics.

when DNS_REQUEST {
  if { [active_members drm-primary-pool ] =< 2 } {
     pool drm-secondary-pool
  } elseif { { [active_members drm-secondary-pool ] =< 2 } {
    pool drm-tertiary-pool
  } else {
    return
  }

}