The horde most certainly train troops, ive seen them even retrain Mongol Heavy Cavalry and Mongol Warriors, thankfully though the horde usually becomes intergrated into the local tribes, instead of training Mongol type troops they usually train local steppe cavalry, slavs, steppe heavy cavalry and woodsmen, they start playing a larger part in Mongol armies and there armies end up a cross of mongols, steppe tribes and polish/russian.