Ben,
You know this but let me state for other readers...
Traditional Kenyan are those TBH with sloped sides and Tanzanian are those with straight sides. Beyond that easy and quick definition, which I think leaves about a thousand other styles undefined, and mislabeled as such.
Throwing in other designs and trying to define what you have is almost certain to be incorrect. Some see beyond Kenyan as more than just sloped sides, and many see tanzanian more than anything with straight sides. Some have suggested that Tanzanains design calls for medium length comb, while some argue what the sloped sides should be defined for the Kenyan.
I have seen a few "trench style" TBH utilizing standard deep boxes either cut and joined or made with one piece of wood. I call my TBH that is made from standard deeps as a trench style design. It does not fit with some of the definitions of what a Tanzanian TBH is called, although it is made with straight sides.
I personally think there are many designs and for a simple classification of sloped or straight, Kenyan or Tanzanian can define that.
Here is a pic of my trench TBH, which I'm sure looks nothing like anything they are building in Tanzania... :)