the biggest problem with the later eras is that they cover such a large amount of time
doing wars in them will be very awkward
yeah, there really isnt a good way around it, one way or another its gonna take longer than it sould
all of those later conflicts werent decided by like 4 battles as they were during antiquity or medieval times
idk, maybe do some sort of "front" simulation? north, south, east or west (or all that are applicable) with factors that determine who is "winning" each front (assigned % out of 100)