As a trader I carried over 1,000 and yes that is not reasonable to do, my trader went from a 5.5 speed to a 1.8 speed after penalty. I 100% agree there needed to be a herd penalty, armies running around with 1,000 horses and 5,000 days of food is not realistic, all I said is need to give "traders" a way to mitigate some of the penalty since it takes over 1500-2000 days to get everything has a price before the penalty, now it could take around 3000 or more, my simple solution, change the Aserai culture bonus from - barter penalty to maybe 25% herd penalty reduction because for a trader 25% herd reduction to the penalty really doesnt do a lot, but to get a 10X greater herd penalty and moved everything has a price from 225 to 300 has made playing a trader not worth doing
Currently you can get at least an additional 50% carry space by picking the right perks. IMHO the major problem is the small price range in the current economy. I did not ran around with that much horses, the profit has gone down a lot thanks to the smaller price ranges.