There are many different ways to play this game. Not everyone is going to play it the exact same way you do. That is why this game is so great. You can be successful playing more then one way.
As for nobling barbs, sometimes its necessary. I don't know who you are talking about or what they are planning but sometimes you can noble no more in your area and want to start a new cluster so you noble a new cluster of barbs in a new area. I personally don't like this method but there is nothing wrong with it.