Brett has a billiant idea (which I assume he may have gotten from the libertarians…. ?). Why speak of liberal v. conservative theology? Or Protestant v. “Romanist”? Why not use a more expansive grid in two dimensions?
My only advice is to rotate it 45 degrees counterclockwise so that “Reformed Catholic” comes out on top.
Why stop with generalizing to just two dimensions? (Why assume that two dimensions captures all relevant aspects of the phenomenon you wish to describe?)
Why not use n-dimensions, where “n” is the number of dimensions that you think are relevant to what you want to describe?