Dualism: In my module I renamed it to Ethics so I could add some tricks to it (City States civic iirc).
Polytheism: I always thought of it as Mythology (and plan to rename it in my module). I think Mythology can cover everything that Polytheism can and even more.
This is workable. Ethics would fit into the tech tree better to lead into Code of Laws without too much risk of doubling religions because of the additional need for Monarchy. I would probably make Ethics require either Priesthood or Trade.
Mythology is also good. It could take over Oracle; Priesthood has 7.5 tricks right now. I'm also looking for a way to to divide up Ceremonial Burial. I don't like having so many religious techs in the Ancient Era, and I'd like to increase Ritualism/Mysticism to the point where I can carve out Stargazing. Mythology could take over Pyramids. Alternatively, Priesthood could keep Oracle but require Mythology.
Ship Building, Fermentation, Sculpture and Warfare are 4 of the 7 techs in that column that can be moved. Move any 3 of them and we have 2 columns having 4-4 techs.
(Or am I missing something important?)
You are missing something very important. Each column contains only techs of the same level, and I want to keep all of the techs at a given level in the same column, but a level could be split into 2 columns if it has 9 or more techs (Ancient-3, Classical-2, Medieval-2, Transhuman-2, and Transhuman-3 are all like that; if you see two columns with NO connections from a tech in the first column to a tech in the second, you're looking at one level that was split up). Scriptures would be the solitary tech at Ancient-5. Columns are also how I cost techs. Techs in the same column all have the same cost.
I'm seriously looking at moving Scriptures into the Classical and letting it move Judaism up. It would be one of the earliest techs in the era. The Judaism-Buddhism line would still be a potential problem, but I don't think it would be that bad.