I almost stopped reading The Grand Etteilla when I reached the minutiae of tables, spreads and examples at the end. I’m glad I didn’t because the “Inverted Pyramid” relationship spread gave me the inspiration (although I tweaked it drastically) for one of the more practical and useful partnership affinity forecasts I’ve come up with so far.
I think this spread will be enlightening for any situation involving the interaction of two parties (personal, social or professional), both potential and existing. It could even be used for corporate entities contemplating a merger. Another approach would be to intentionally choose one or both of the two “principal” cards in Row #1 (Cards #2 and/or #5) when known qualities are involved, and pull the rest randomly. This could make Elemental Dignities especially valuable as amplifying information.
Parsifal's Wheel Tarot & Astrology 