Ken
I'm sure you are right - that it is designed to work in groups - however history tells us that you can't guarantee how you will have to fight in reality. “No Battle Plan Survives Contact With the Enemy”
Helmuth von Moltke.
the other point is that I doubt many (?any?) of the non -US buyers will have the IT, networking and other sensor capability to actually form a "group" - they're planning to use the F-35 as a straight replacement for 3rd & 4th Gen aircraft