That would work jn theory, you can stack any combination of the stages 2 to 4 end to end to make a combination. But I don't see it as the way to go for working with rotaries because each stage would need to have switch, which if translated to a rotary controlling all the stages, would need to be a separate pole, one per stage.
My current sketching around this is to have Stage 1 as designed before (design M or M2), then a single stage after that where each of the two resistors is a chain, selected by a switch, so two poles, and as many steps as can be found based on switch positions. If an 8 position 2 pole switch can be found, then that would do it. If it's a 6 position switch, then Id augment it with another high/low toggle switch to extend the range while keeping rotary increments small.
I have a heap of maths built into spreadsheets to deal with this stuff, but the trickiest step currently is to find a recipe that works with the limited range of resistance values that are available from normal suppliers. Definitely solvable, just a bit of a PITA!