So I have a very different viewpoint on squads.
Most people like to put the maximum number of people. I think that makes logistics difficult both in the getting the squad around as well as for the overall commander to fine-tune the number of players assigned to each task.
Most people like to have "one-of-everything." I think that makes the squad mediocre at everything. I would rather have the squad specialize and then have depth and redundancy at 1 to 2 tasks.
I have not seen a limit to the number of squads (unlike
BF2) so I would actually limit the squads to 3 players...A squad leader and 2 fire-team members with the exact same kit and role.
If you only have 1 anti-vehicle in your squad of 4, your squad is not going to kill that tank before suffering enough casualties that you really cannot continue. Even worse, if the tank kills that anti-vehicle player, then the tank can mop up the rest of the squad pretty easily. It's easy for either of these to happen especially if the anti-vehicle player happens to be in an bad position to shoot first.
Now, if you had 2 anti-vehicle kits, then your squad can kill armor so quickly that you won't sustain as many casualties. Or, if you do lose one AV player, you still have the other to soldier on.
Way back in the Desert Combat days, we rolled like this...
* 5-man squad in an armor-rich environment = 2 spec-ops, 2 anti-tank, and 1 engineer (driving armor).
* 4-man squad in an armor-rich environment = 2 spec-ops & 2 anti-tank.
I think that 4-man loadout still works today. I would merely change the anti-tank to assault on non-armor maps.
As far as kits, I think that knowledge and information are more importnant than supplemental weapons. That means Drones and EMP (gain and deny enemy location, respectively).
Below are some slides that I developed first for my clan bootcamp and then for 21CW bootcamp. They are very BF-centric.