It is all about goals and they are vastly different between regions , cultures and person to person. To accomplish any pond goal you have to know your environment (waters) and the available tools and then match the goal to the environment. There is no single right or wrong answer only the application of available tools to the goal at hand. There are however some biological (chemical) principles you have to account for. You can only fool mother nature a little before there are consequences. Water quality and one of its functions carrying capacity are at the top of the list. Push that to far and you will have problems. Its like an engine - you run it at to many rpms for to long and it will break. It is always a good idea to leave some leeway (space , buffer etc.) available to protect against unforeseen events like weather and human mistake.