Endinku asked why is it that most miniature handlers do not want the smallest horse in the class.
The answer is because a small horse is going to have a hard time beating a much taller horse. Lets say the class is 34-38" 4 inches is a huge difference in minis. It will be very hard for the 34" horse to beat the 38" horse. The taller horse is going to look leggier, probably have a longer neck etc. so while its not impossible for the smaller horse to win, odds are it will not.
So if I had a 34" mini I would show it in the 30-34" class and be the tallest horse in the class as opposed to showing 34-38" and being the smallest horse in the class.
Some people mistake what the AMHA AND AMHR rulebook says. They think it says "the smallest horse must win"
It actually says "if you have two horses that are equal in every way, the smaller horse should win" (paraphrasing)
It is very rare to ever have 2 horses equal in every way. So this rule rarely is ever used.