AFAIK, this is an 'old' feature in Ensemble to allow you to have two different sets of config for a component so that you can quickly switch between them. For example, you could use it for switching between different environments for testing interfaces. You would have a different class, but the same 'Name' in the production. I suspect you've got this duplication inadvertently.
But, my recollection on this is hazy, so perhaps someone else can add a better explanation.