Clan System
Not necessarily a clan, but a "Company" that sub contracts for the PMC factions. These companies are locked to whatever faction the founding player belongs to. This could come with the ability to form larger groups, preferably 16, but 8 would be a good middle ground. Additionally these companies could also design a patch worn on the left sleeve, currently the faction patch shows up only on the right AFAIK
UH-60
If allowed to form company squads bigger than 4, the MH-6 Little Birds wont be big enough to transport the whole squad. The addition of UH-60s could facilitate larger group transportation. Company Squads could still have the option to select the MH-6 when selecting the LZ.
Hot Insertions
With the addition of UH-60s, a cool feature would be the ability to conduct hot insertions directly onto major points of interest ie Fort Narith Command Building. AI door gunners could engage enemy AI as the squad fast ropes onto the X. Companies can earn "tickets" via dynamic squad missions that allow them a Hot Insertion into major POIs.