I didnt notice you replied close to a year ago, big apologies on my end..
So with the Simple and the Quest NPCs, NPCs (VJ base from my testing) attack the respective Idle/Quest NPC.
Id like to suggest like a health system for them or an option to notarget them. If you do add a health system to either, can the respawn all NPCs option in the Setup Menu respawn the Simple ones too?