I've mulled over this for about a month, and run a few experiments regarding picking in Arcanum. I've noticed that certain characters, regardless of their level, are much more difficult to have their pockets... picked. Archers and gunners, primarily. If this is the case, will a high perception give an NPC more pick-pocket resistance? I'm one of those hotkey whores who buys an item and then picks all the money back (spamming F7 and F8 *autosave*): I noted that it was easier to pick an NPC's pocket when I gave them a pair o' shades (planted the item in their inventory). Most shopkeepers tend to have competent perception, meaning the glasses reduce their perception. Easier to pick. I also noticed that Virgil will occasionally try to pickpocket you or another NPC-- he tends to take health pots. :/
New to me, but if it works, give them a helmet for 1 less PE. Also new to me. Simply disable follower skills if you're 100% sure.