I wrote a little about it back then: https://hive.blog/hive-173286/@phoenixskye/preview-of-daily-pay-and-earn-percentages-according-to-rank-and-deck-quality
Basically 3 Diamonds + 27 Meteorite is better than 30 Shadow. However, even at that point, you're just only 4% more than a 30 Meteorite deck; the most important thing is staying in Mythic.
I just re-read your post. You might be right about the impact of ranked. My hope is that the impact of rank is not as dramatic. There won't be any way to know, but if I was designing a system, I'd more or less equally weight shine and rank. That way, mediocre players with high shine could earn similarly to star players with low shine.
Even if your interpretation is correct, I think 2-3 decent 1 drop diamonds is still probably the way to go to keep your win % as high as possible.
Fun to speculate.
Well, technically it is weighted equally as rank and shine carry the same weight; a full Diamond deck playing at the lowest rank gets more or less Gods than a full meteorite at Mythic