Are you back to discussing the need for one vehicle to do everything? Carry troops, kill troops, kill vehicles, kill tanks, kill RAM, UAVs, helicopters, and Fixed Wing?
Or are we considering the fleet in its entirety?
All vehicles, regardless, of their purpose, are going to be under threat from RAM, from Loitering Munitions and from Micro and Mini UAVs. All vehicles then, like all ships, are going to need point defences to counter attacking munitions at very short ranges by means of obscurants, decoys, EW, DEW and kinetics. That means the C-RAM system needs to be full spectrum, low volume, light weight and cheap. This point defence system needs to be limited to one system per vehicle on account of cost and the need to get the job done without interfering with the vehicles primary function. That suggests a single turret mounted system rather than a multitude of fixed sensors. It also suggests a highly autonomous solution with all aspect sensors, rapid slew to cue capability and the ability to depress below the horizontal while elevating as close to the vertical as possible. And it needs lots of ammunition.
It has to be compatible with any vehicle for the 7 tonne JLTV class, through the AFV/IFV/APC fleet to the CS and CSS fleets.
And it has to be able to manage dismounted troops as well. It should be expected that it will work in packets of 4 or so vehicles working in conjunction.
And, did I mention that it needs to be light, effective, not interfere with the vehicle's primary function..... and be cheap.
Once that is done then you can start building the fleet with dedicated functional platforms for multi layer AD, multi layer AT, Assault, Troop Carrying, CS and CSS capabilities.
I don't think we can rely on being able to cluster a large number of vehicles under a single, tight umbrella. To deal with dispersal you are going to need lots of small umbrellas. Ideally one per vehicles but at least one or two per packet.
At the one per vehicle level the effectors are EW/Laser (DEW)/ small calibre, very high Rate of Fire machine guns - something like a 5.56 gatling gun or chain gun.
At the packet level you are up to the auto-cannon level (20-50 mm) that operate in the 2-5 km max range bracket. At that level you may also be adding VSHORAD missiles in the MANPAD range.
What do you need for defence if: ou are operating as
packets of dispersed vehicles with constantly changing compositions,
platoons and troops of fixed compositions and platforms
independent companies, squadrons and batteries
independent battalions and regiments
independent brigade groups
an independent divisions
all of the above but operating in an allied context
Seems to me you have a lot of work ahead of yourselves, Especiallly for an "Army" that struggles to field 18 infantry companies, 3 tank squadrons and 6 gun batteries.
Edit: Dam! I wish I could type faster.