A dog is not really a puppy after a year, although many owners would like to think their dog is still a pup. Maybe, not fully mature, but not a puppy either.
I've selected and trained many dogs at 10 months to a year old, mostly Malinois and X's. But, I have had GSD's ready to go at 12 months and make it through training and are very sound Patrol dogs. When testing a young dog I look for slightly different things, I look for confidence over civil aggression. The testing is similar, but I absolutely take age into account. I want a 18 -24 month old dog to try and bite me for real, with serious aggression when back tied and I have no equipment. A 10 month old that stands his ground and is very confident is a good response for me.
Boomer was doing a full IPO 1 routine with a serious edge and outing by 9 months. He would bring it seriously and confidently at 12 months, he is not your average GSD though.
“Beware of false knowledge; it is more dangerous than ignorance”. George Bernard Shaw