If the player, as group leader boards an unarmed vehicle in a cargo position, they lose the leadership of their group formation (AI units in their group expect the group leader to follow them, not the other way around). This issue does not seem to affect armed vehicles.
If the player's vehicle is commanded by a member of his group, that unit inherits the formation leader role. However, in other circumstances, some other unit takes the formation leader role. Here are some possible game circumstances where this is a problem:
- Leader boards vehicle in cargo position, then moves to driver seat and drives away. His subordinate units will order him to return.
- Leader boards a vehicle driven by another group. That vehicle moves away and his subordinates will order him to return.
- Leader orders a subordinate to drive an unarmed vehicle. The player then boards the vehicle. If he orders his driver to move to another location, and then they both dismount. From then on, if player asks his AI to return to formation, his avatar will say "Join Group" and AI will return to whichever unit may have the group formation leadership (it will be neither the player or his driver).
Unless ordered to do otherwise, the formation should follow the group leader. If their leader boards a vehicle and moves away, they should follow rather than order him to return.