[Aramid]

This is just a thought off the top of my head!

I would think that these NPC's have a Spell Set assigned to them? As a test, remove their spell set and see if they still cast a pet! If not, then an adjusted spell set may be the key for these NPC's

Going to answer this myself. It works. If they have a Pet Spell assigned to them, their going to cast it.....

I removed the Spell ID off an NPC in The Nexus who always cast a Pet Spell, when I removed her Spells, she no longer had a pet.

So, you will have to make New Spell Lists for these NPC's without any Pet Spells in the list. If you remove pet spells from the Default Lists, no one will have a pet that uses that Spell Set.