How to deal with branches in the entity dimension?

Summary:

We have branches in the entity dimension, which are not legal entities. How to deal with these in Consolidation configuration rules?

Content (required):

We decided to put branches in the entity dimension and not in a custom dimension to spare one dimension. These branches are base entities, but no legal entities. Equity should not be eliminated when consolidating, so the consolidation menthod should not be Subsidiary and also not Holding (although that might technically work as there will be no data on Investment in Sub). Should we create a new method for non Legal base entities?

Version (include the version you are using, if applicable):