Here is the 8 horse Budeweiser Clydesdale team, demonstrating the days of old when a wagon would be at a loading dock and the team would first have to position the wagon at the dock, and then to clear the street for traffic swing the entire team a 90 degrees (or 180 in this case) around to make room. This is obviously not an easy thing to do or train the horses to do.
The front horses are called the lead, the second pair are the swing horses, the third is the body horses, and the last pair closest to the wagon is the wheel horses. Notice that the front horses are the smallest, most nimble of the team, while the wheel horses are obviously the biggest and stoutest of the lot. On average they are 18 hands tall a piece. A hand is 4 inches, for you non-horsey people. That means that they are 6 feet tall at withers (the area where the neck meets shoulder and back). Pretty huge animals.