Guardians are not charmed. Vehicle requires that flag only if player controls vehicle. It has absolutely no impact to creatures which are mind-controlable \ enslave-able. Their default AI is blocked during mind-control \ enslave as intended and you definitely don't want to make them cast spells from their SAI or execute any other action if they are mind-controlled or enslaved.
Ref #26065
(cherry picked from commit c00b0551345245c2a91db2e1b62a13fa969c218e)
offl
601a414f7a