Yeah I work at a barn where the majority is arabian and saddlebreds. Alot of the pure arabians are pretty short ranging from 14hh to 15hh, but we have gotten a new stallion who is probably 16hh. I am not sure if this is correct or not, but I heard a rumor that arabian breeders are trying to breed taller horses but like I said I don't know if that's correct or not
Same that other breeders breed for colour, or dish, or small feet, or whatever.
I generally like my Arabs are 14.2-15 because I find horses that size generally have better hocks and can get much more "catty" than the taller horses.