I was thinking about this and I started looking up more info on Roman wars. I know the Romans were a very dominant force but why did they engage in these battles so much more often than the Kingdoms and Duchies of the medieval era? Was it mainly because of christians not wanting to kill their fellow christians which made siege warfare the name of the game? Or were defenses not really good enough among the Germanic, Asian, and African tribes that the Romans pretty much could storm the place?