Hopefully I can make this clear with an example. On my current keyboard, Alt is directly under X and Win is directly under Z. On most of the models of mechanical keyboards I have looked at, those keys are shifted well to the left of where I am used to. The bottom row layout is often (3 keys, spacebar, 4 keys). If I could switch it to (4 keys, spacebar, 3 keys), that would match what I am used to.
I am testing out an Aula F87, and I've found that the difference is not just cosmetic. I use the Alt and Win keys a lot between video games and my window manager, and it is substantially less comfortable to have to reach the additional distance so frequently.
How much work would I have to do to, or is it even possible at all, to move things around as described? If it's not possible, does anyone have suggestions for finding a keyboard that matches what I want (other than just looking at pictures of lots of keyboards until I find one that looks comfortable)?
I'm late here, but while it may create more problems than it solves (it also uses an ISO style vertical "7-shaped" enter key and splits the right side shift), a JIS keyboard shortens the spacebar and does 4-1-5 on the bottom row. If it's remappable you could make the one immediately to the right of space be another space so your thumb doesn't betray you.
Beyond that, "Minila" layouts are usually for smaller boards (60%) but will sometimes have this, and if you can at least go as far as soldering switches, YMDK sells a cheap PCB that has many bottom-row options. If getting left-Alt moved to the right a bit is the main thing, many custom and semi-custom boards support the "Tsangan" bottom row that scooches it so it covers 3/4 instead of 1/2 of 'X'. Finally, the Tex Shinobi is a mechanical keybaord that recreates the layout of a Thinkpad, including the trackpoint.
Or, you could go full DIY. C'mon! You know you want to!