I had a bit of time to check this, it seems that all normal industrial beacons have a configuration of 10-7-5 waves so I'm going to assume that's intended. The reason for this setup was probably balancing: indy beacons are basically a no-effort bonuslevel duckshoot and the higher NPC ranks in 2/3 stripe beacons have already nice loot without having 10 waves of them even.
But you're right about the Pelistal Squad, it's missing the elites.
Also, the Praetorian Captain beacon (3 stripe) used the pool of the Praetorian Corporal (2 stripe).