If you want to watch an awesome carriage trainer check out Barry Hook on youtube from Britain. The man is very skilled at retraining horses for driving and by watching various videos you can watch everything from a single pony to a hammerhead of Friesians. That was a term I'd never heard of but it's a five horse hitch, three abreast and two wheel horses. The middle horse is a bit ahead of the other two, thus forming a hammer head. The traffic he drives in would scare the willies out of most of us and the horses learn to cross a small river.