Ah, you actually saw my comment. I removed when I realized why you did it, but thanks for the reply anyway.

(Part 1)
The switching of the main and Ikko techs wasn't a mistake, that's the only way the mod works.
When trying to edit tech trees, the game insists on retaining existing connections. Adding in new connections works fine, but it will still retain the original ones, even if you swapped them over to something else, resulting in a tech requiring both the old requirements, and your new ones, so that a single tech might need 4 different techs to be taken. This game's modding tools are really picky about trying to keep things vanilla.

(Part 2)
The only way to break the techs connections from where they were originally was to remove them from the tech *tree* that they came from, so that they would have no existing possible connections, and then I could hook them up as needed. The actual effects of the techs are completely unchanged, and there's actually zero reason for them to be duplicated for the Ikko Ikki, but it made it convenient for me.
Since they tech IDs actually reference the exact same tech effects, if you use another mod that changes the effects of those techs, but doesn't mess with the tree itself, it will actually be compatible. Unintended, but nice anyway.

This is almost exactly what I wanted to do as well. I would just move 'Form' down one tier and move 'Horse Mastery' to left under 'Gunpowder Mastery'. It always seemed weird to me that you essentially *have* to master horse riding in order to get to 'Shih', but not the others.

Then I would replace the location of 'Form' from before with 'Heaven and Earth', because I think that one feels the most relevant to attacking and gunpowder. Instead I would create a new tech where 'Heaven and Earth' was before.

Like this: https://imgur.com/a/dqrcWTx

Thanks! It felt like such a small change when making it, but I really like the end result so much more.

This is actually quite clever and makes a bit more sense when investing into gun units.