Nope. In my experience (usual disclaimers about not necessarily being exactly true)
Neutrals will attack FRIEND (BLUE) or ENEMY (RED) alike when they feel threatened.
Also, the AAA/SAM logic is different from the SSM logic. I believe the ships will engage for self protection regardless of the waypoint setting, while they need to be told to attack surface targets along the path.
Must they be OSA? You could make them some other ship without Air defenses and leave them NEUTRAL.