Makes me think of "In-breeding"
I've seen quarter horse bloodlines a hundred times worse than this. This is nothing in comparison to other horses I've seen. (not picking on quarter horses. I've seen horrible inbreeding in lots of breeds).
Anyway. Demons Fire:
Sire was very nice. Winner of some nice races at 2 and 3 and even raced at 4 which is rare nowadays. Dam raced a lot 24 starts also rare these days. Tells me sire and dam are probably tougher than the average retire at 3 horses these days. Let's see Halo, Nasrullah, Count Fleet (triple crown winner) on sire's side. Bold Ruler, Swaps, Raise a Native, Nasrullah again, Nashua, Native Dancer, and Bed o' Roses on dam's side. I'd say dam's pedigree si very nice.
Wow, wow, wow. Unbridled line. Let's see sire is WOW. Winner of some very good races and sire of good horses. Dam raced 42 times unheard of nowadays for winners. Won and placed in ungraded stakes it looks like at 4 and 5. Other than that we have Mr. Prospector, Dr. Fager, Raise a Native, Flower Bowl, Bold Ruler.
I don't know about breeding them. The foal will have a lot
of Native Dancer and Bold Ruler. Little too much inbreeding if you ask me. The mare has amazing lines. If you really want a racing foal I'd suggest finding a proven stallion without so much Native Dancer.
Just my opinion and I'm definitely not an expert.