Group the tanks like this in the leaders init field:
tankgroup = group this; tankgroupnumber = 4
And in a trigger type this:
cond: count units tankgroup<tankgroupnumber
on act: hint format ["%1 Tanks Left", count units tankgroup]; tankgroupnumber = tankgroupnumber - 1
Assuming you don't want the tanks in the same group, group the tanks with the trigger and replace the above on act field with:
on act: hint format ["%1 Tanks Left", count units thislist]; tankgroupnumber = tankgroupnumber - 1
Or something like that. My OFP editing skills are a bit rusty so it will probably not work(or there's an easier way)but you get the pic?
:beat: *Gets Shot* :beat: