This race is so wide open that all the horses with "suspect" preparation going in might lose and it could have nothing to do with preparation. If that happens, after the fact, everyone will again point out their favorite negative stat, but it will be hard to know what caused the defeat.

IMHO, issues like seasoning and being prepared to go 10F are almost obvious factors, but you shouldn't apply hard fast rules to the race. You should look at the specifics of each horse.