G1 Pony wear question

[Cactusflower]

I finally decided to take the rest of my pony wear out and dress up some ponies today.

So friggin' cute, but I have a question - Does the adult prima ballerina costume fit ANY pony? I tried it on Cotton Candy, Glory, and Lickity Split and it wasn't even close to being able to reach the velro closure. I tried a second outfit I had and same thing. What gives?

 

[CharmsPonies]

Different poses you might have difficultly fitting certain outfits on. I am not sure about that specific pony wear