Yes, they do have the same sire (not sure who though--I haven't looked at the breeder's website.) I was curious about their potential because the chestnut was marketed as "extreme top hunter prospect!" and the bay was simply marked "hunter prospect". I was actually thinking about buying one of these two or a similar filly to do lower level hunters and equitation (leaning towards the bay). I'm finally stable enough that I can buy another horse and I'm just itching to get one, so I'm looking at a lot of TB fillies lately. These two really stood out to me, not just because they're pretty but because OMG the seller actually bothered to make sure they were relatively mud-free and stand them up at a halfway decent angle!