marathon dont be stupid. mount & blade warband/crpg is set in middle ages. even today no one uses 17th guns in military.
so the medieval ppl didnt use acient stuff either.
False. Medieval people used lots of ancient weaponry. They used whatever was on hand, actually. And where do you think seige towers came from? Most effective seige weaponry was designed in the BC and remained effective weapons until the advent of the cannon. Some weapons remained in use and unchanged in style for almost a thousand years before gunpowder changed everything. Look at the bow and arrow, for instance. And yes, the Pilum was still in use in the middle ages even if the roman armors and shields were not.
One of the main reason the roman armors were discarded was that they were too expensive to produce. Rome, as an empire had vast resources. the small fiefdoms that emerged after its collapse, did not. and yet... the style of roman armor still endured and transformed into more inexpensive armor types, like the
Cuirass which lasted through most of the middle ages and well into the age of gunpowder.
Your assumtions, sir, are wrong.