YOU BRING THOUGHT TO MIND GUD SIR
Why is Princess Celestia and her guards about 3x taller than everyone else? Are they actual horses or something?
Assuming all the normal ponies are terribly short, Celestia might be at the top of the threshold of being called a pony, 14 hands.
Her guards are probably hand-picked stallions, the biggest you can find. It'd make sense, in real life it would be intimidating to see a giant man versus a stumpy midget guarding somebody.