Well all the lords combined are sure gonna add up too a decent amount of troops. You dont have enough towns fiefs etc to have an army around 900, or hold off if its just you. Get some lords on your side, open up enterprises. I own a army of 500 plus each of my 5 lords roll around with 250+. Cant really one man army the game. I only own 1 city 2 castle and 4 villages. Cant grow yourself too fast or you pay for it.

I just don't understand how they can deal with the upkeep. I mean, 8 or 9 lords attacked me with a total of 2700 troops. They literally only have 3 castles and 3 villages between their entire force. They have next to no economy going for them., There is no way they could afford the upkeep. They don't even have any cities anymore. Plus I have enterprises in every city on the map. My weekly army costs are around 35k denars, and my income from all of my enterprises, city, village, and castles comes to about 15k.

I would just summon the other lords to help me out, but for some reason my leader decided to cancel me being the marshal about 10 days in, and gave the title to someone who just marches around the map doing nothing. I honestly don't think the AI has to deal with an economy. There's no way they could afford to field a force that large.

Go to the lords descriptions and see how much money they actually have. It is possible that some lords accurated 100k-200k denars and are able to buy reinforcements / pay upkeep even without holding any fiefs. There is guaranteed ”weekly basic income", but is rather low (lord will be able to recruit only few weak soldiers weekly).

Thanks for the reply. I just checked, and yeah. One of them has 130k. I guess they can accumulate a lot of wealth by the time day 690 comes around. :S