How many Breyer Stablemates are there?

There are literally thousands of Stablemates. Breyer's website (see related link below) has a list of some... A few months in advance, Breyer releases it's FEI World Games collection (which has eight or so Stablemates; one for each event). Otherwise, there are numerous kits such as the Saddle Club sets. And, there are the normal SMs that represent their breed: such as the Arabian.

newtest3

Actually, there is an infinite amount. If you customize one of the zillions created, you made a new horse. This is true with all Breyer models.