Neon - I totally understand where you are coming from and in a lot of ways I think triads can be much more complicated to navigate than individual polyamorous relationships. So to that end, I don't subscribe to the idea that triads are a "preferred configuration" for couples new to opening their relationships. It may seem simpler/easier, but it is SO not.
The reasons I think we are most hypothetically interested in pursuing a triad (or maybe even a quad) was our original experience that sort of fell into our laps and how enriching that was even though it never moved into a poly-relationship realm AND the fact that my partner and I are just very close and we are most often together. Some may see that as problematic but it is just natural for us since we are best friends.
That being said we would never force a connection where there was not one and we are very open to being surprised by our future path.