I did a bit of research on this the other day, and I thought horses making their debut actually came out pretty well overall. Can't see enough evidence to suggest it's a big negative myself.
Have you got the 'working' CCM? It is one of that stats I have just always assumed without checking fully myself.
I see Ista says in the Nov/Dec meetings they don't do bad either?
It'd still put me off, unless it w3as a wild price, and SS wasn't a spectacular horse, but interesting for moving forward...