this is a REALLY odd percentage. The only thing I can think of is they got it by crossing a 93.75% Dwarf with a mainland to get that percentage mark.
It's a good reason to think that it will probably be smaller as long as the female was the close to pure dwarf, and the male was the mainland. But it's definitely going to be questionable. For those who want to know how I came up with this number and how I THINK the breeder came to that % . . . it would look something like this -
Pure x Mainland = 50% Dwarf (Gen 1)
50% Dwarf x Pure = 75% Dwarf (Gen 2)
75% Dwarf x Pure = 87.5% Dwarf (Gen 3)
87.5% Dwarf x Pure = 93.75% Dwarf (Gen 4)
93.75% Dwarf x Mainland = 46.875% (Gen 1 - since its back to mainland)
which is pretty dang close to what they are "representing"
Case and point - since you have a male, it will likely stay on the smaller side as long as you do not power feed it. Welcome to the retic world. Always practice safety and know your laws.