That's a fair point, though if you just care about LoC's, the point is moot, and they'll eat a perils when you hit. Nids, I think the only guys this ruling has bearing on are brood lords and tyrants with a tyrant guard unit. Can Alpha's get psychic powers?
I forgot about the allocation difference. based on that, you'd never get to trigger the perils even with precision, because the unit is still a tactical squad, not a tactical squad with a librarian, in the above example.