OK, let's compare it to the 18-month existence of the US's Pony Express (April 1860 - October 1861).
The distance from St. Joseph, Missouri, to Sacramento, California, was about 1,900 miles. Covered in 10 days, that meant 190 miles a day ...
But the article in Wikipedia has almost as many inconsistencies as HoMe ... 😳
"In 1860, the roughly 186 Pony Express stations were about 10 to 15 miles (16 to 24 km) apart along the Pony Express route. At each station, the express rider would change to a fresh
horse, get a bite to eat, and would only take the mail pouch called a mochila (from the Spanish for pouch or backpack) with him."
"Along the long and arduous route used by the Pony Express, 190 stations were used. To maintain the rigid schedule, 157 relay stations were located from 5 to 25 miles (8 to 40 km) apart, as the terrain would allow. At each "swing station", riders would exchange their tired mounts for fresh ones, while "home stations" provided room and board for the riders between runs. This technique allowed the mail to be moved across the continent in record time. Each rider rode about 75 miles (120 km) per day."
So it appears the riders changed
horses on average every 10 miles. For
Gandalf's ride, this would have meant 34 changes of horse ...
Then there is the bit about every rider covering about 75 miles a day. To reach the required 190 miles per day, they would have needed about 5 riders per 2 days.
Ah, there's another quote belonging to the first one above:
"Riders, who could not weigh over 125 pounds (57 kg), changed about every 75–100 miles (120–160 km),
and rode day and night."
Meaning that the 380 miles (average) covered in 2 days by 5 riders were achieved in 48 hours, or at an average of 7.9 mph ...