So what I believe the issue with AI has to do with effective commander of vehicle. https://community.bistudio.com/wiki/effectiveCommander when combat mode "danger" is triggered. If the effective commander of vehicle is driver it leads to spamming of mount/dismount command. If effective commander is gunner then command of movement is spammed. If commander is effective commander then command of target is spammed. If group leader is an infantry unit then they won't mount the vehicle for waypoints.

This is a problem in case you want to script something that relies on CfgGroups, you will need to make exceptions for factions which have it set up differently.