A horse can travel about 30 miles a day, and by the sounds of thing, this 30 hour trip was about 1600 miles. Does that mean they could ride/guide the horses back in about 2 months?
Presumably these undomesticated (idk to what degree, I think they've interbred with domestic horses) horses are not generally interested in being ridden. Besides I'm guessing 30 hours of known issues might be more attractive and/or cheaper than 2 months of unknown issues.
