I loved seeing the movie Cinderella but I am confused about why the fairy God mother changed the horse to a carriage driver? Isn't the horse strong enough?
Because it's funny. The horse expected to be the one to pull the magic carriage. Instead he's the driver and the mice are the horses.
It probably looked more majestic to have the carriage pulled by 4 horses instead of one and of course only one driver was required. There were 4 mice and one horse. Ergo...
Having four friends, (mice), pull the carriage not only saved time, but also ensured a sense of comradery and teamwork amongst the team.
Additionally, it ensures a pleasant evening to have a mute carriage driver. Had one of the mice, who can speak, become the carriage driver, they would have talked Cinderella to death. But by having a friendly and albeit dim-witted person in the lead, as well as the talking characters people rendered unable to talk, you have an ideal and quiet evening.
I suppose you could also say that it's far from graceful to have an ass of a horse changed into a more majestic horse... that sends a bad message about beauty discrimination.