:(edit conflict) Ike, there is the possibility of an article like Triad (theology) or similar. But it would take an awful lot of work to demonstrate that people are talking about the same things. It's interesting that you're using "typology", but in the authors you cite it seems to be the regular definition of typology - i.e. what's in Typology (theology) - without having anything to do with the number 3 necessarily. In Poythress, however, there is a clear theme of using three perspectives to interpret a text. See also Multiperspectivalism.