There is literally a giant in my game, charlemagne, who has 4 vassals and like almost 20 cities and unfortunately for me dows on me. My God, he has 3 stacks worth of 25 units each although purely made of cannons and medieval troops purely overwhelmed my 20 unit stack of riflemen and cannons. He took two of my best cities and my two other vassals aren't doing jack since I am at the frontier of the war. I'm bleeding my colonies dry of draftees just to support the war effort against this giant. My question is what do I do now?