Less hardy? They were renowned for their ability to cover great distances on poor fodder. They still are too, so we don't have to accept historical accounts on faithEinion,Merryweather- yes, the type of a horse was discussed with the customer. I hold the opinion that "similar to a pony" horses at Mongols - a historical stamp. They less hardy and high-speed, than European and Arab breeds. They physically couldn't overcome those distances which are attributed by it. But it is my personal opinion.