You need to look at the social factors as well. Are you looking at a modern world with a middle class and people expecting a decent daily wage or a highly stratified feudal society with mages/lords at the top and everyone else basically serfs.
If it's the former then it's one person with a team of horses. Simply a matter of cost.
If the latter then peasants are cheap and don't need paying. Remember that serfdom wasn't abolished in Europe until the mid 19th Century.
Considering a "modern" society, non-feudal with mid 18thC tech what you want are mules.
Mules are "more patient, sure-footed, hardy and long-lived than horses, and they are considered less obstinate, faster, and more intelligent than donkeys.
They're also cheaper to run as they'll eat less than a horse of equivalent size. We don't tend to breed them so much these days but they were a staple of long distance transport for thousands of years.
Mules have been deliberately bred by humans since the Book of Genesis was first put down on parchment. The Hittites thought Mules to be more valuable than a chariot horse, and the mule was the favored mount of the Kings of Israel in biblical times. The exact origin of the first mule is unknown, but we do know that the mule was deliberately bred by man in ancient times.
On plains wagon trains that used mules instead of horses, they could travel 30 miles a day, while wagon trains with horses or oxen could only average about five miles per day. In the west, stage coaches preferred mules over horses because large mules could travel at 5-6 mph over flat dry land for hours, but a horse would give out long before a mule would.
Mules every time.
