To make sure people stay in their group/squad, how about we reward them with extra XP if they accomplish their objective as a team. Like if the members are within 300m-400m from squad leader will get XP bonus. Mix squad from member of different squad does not count. Those that capture bases lonewolf or with mix squad only get minimal XP.

For logi players, maybe squad leaders can make objective "supply Y base" then a member from his squad accepts it (like the J key listing the objectives) once he completes the supply mission, he gets the extra XP. Those doing lonewolf supply run gets minimal XP.

Maybe can be implemented to the commander role once that feature was implemented.