GWS are not a good example, they had so many picks they could afford a high failure rate. They also didn't have players ahead of those kids to keep them out. Playing kids before they are ready hasn't worked for Gold Coast, hasn't worked for Melbourne, didn't work for Carlton, hasn't worked for Brisbane. But the bolded part you are essentially saying you wait until the player is ready, if they are doing all the right things and there is a spot for them, then they are ready. Craig didn't think walker was "doing all the right things" that's why he held him back.