WMW, many many racehorses have conformation flaws. It’s the sale horses that look perfect, and many of them have had surgery to make them appear that way.
If someone were to decide that horses who didn’t have perfect conformation were at too high a risk to be racehorses, racing would shut down. Right then.
As would eventing and show jumping, if the same decision was made regarding their entrants. The majority of horses, of any breed, are simply not conformationally perfect.
When new stallions retire to stud, I go have a look at the ones we might be interesting in breeding to. More often that not, I look at these very accomplished racehorses and think, “You ran so well with that [flaw] ?! Well okay then.”
We’re all trying to breed perfect horses but it seldom happens. Mostly it’s a matter of deciding which small flaws you can live with.