[Inquiry] Please provide clarification on "Link a Device"

I just did this. The device you are going to needs a new fresh game on it to over ride. So when I went to put it on my iPad I made a new account link and it was override. Now if you want to from a friends iPad to you. You need to link it first to a none Apple product to unlink it from Game Center. Then relink to the iPad. One more step is not bad. It’s a good way to and easier way then bothering them to do it