At 12 months old i would expect the dog to either go for it or jib, they either will or won't, why wait til it is 2 years old ffs, most dogs are adults at 12 month old, the latest i would hold out is 18 month old for a large bred dog. Dogs that are bred from late starters produce late starters in my eyes, if they jib they jib they obviously aint going to be a regular single handed dog. Just my personal opinion but each to their own, if your happy with the dog regardless then who cares if it takes red coats or not.