> Everything else has a meaning-based mnemonic, and until I read your post I hadn't ever thought about their position

My point is that position is the primary thing that's important for an editor when used for a long time. Your hands and fingers move in physical space, not over alphabet. They get tired and maybe get repetitive strain injuries over real movement.

Mnemomics way of setting up keyboard layout (or rather typewriter) would be to put everything in alphabet order. But we quickly realized that it's not a good way. `d` is where it is because according to (imperfect) research it's a common letter and so in QWERTY layout this letter should be on your home row.

Putting A-something on `a` because the word starts with `a` is not a long term design. Considerations should be based on usage. How often is this used? Put it closer to home row. Is it designed to be often used with another command? If often, those two probably shouldn't be on single finger. And so on.

There is argument for easier start - except that I said already - modal editors are unusable without reading docs first, so that argument doesn't really hold.