All the stories I’ve read all say the same thing in the end. When you start out and you and your horses are fresh the urge to push and make miles will be there. But all agree that in the beginning try not to make that mistake. Do no more then 8 to 10 miles for

the first few weeks then move them up a little each week till you are doing anywhere from 15 to 20 miles a day. Don’t be pushy if you find a good place to camp at 10 miles take it. They also said that the urge to push hard will take you at the half way point because at that point you and your horses are fit and seem able to go on for ever. But again don’t push. Same as near the end if the Trek, at that point you start thinking that you’ve made it and you want to get to the end. That is when your horses are the most vulnerable because they are tired and are easily pushed to hard.
The idea behind my Trek isn’t the destinations end. The destination is the mission and the experiences on the way is the dream. The hard part will be remembering that.