Specialized crews and squads
(I know this isn't ever going to be added and there are a more important things but let me dream damnit.)
Currently there is no way to "specialize" a squad for a certain purpose, every squad is kinda like a jack of all trades. Defensive, offensive and artillery squads are the same with only slight variations. While you can set up a MG squad with like a rifleman or support for ammo, and a SL looking for targets, but that leaves the ammo carrier almost useless without an active task, and if they die doing something else, the MG is left without bullets.
And if the squad is not locked, it leaves the rest of team without a SL or if it's locked, the squad may look useless for others.
It would be interesting if there were specific roles for squads that would make everyone in it work together, like in artillery or AT cannons where both users contribute and get rewarded.
MG crews where the gunner has less ammo but there's a ammo carrier/feeder that could feed constant non stop ammunition, AT crews with with extra missiles and AT mines on support with less supplies, support crews with less firepower but more supplies and droppable ammo etc.