I did a little reading on them and came across a description of how they write music:
During songwriting, Hagström programs the drums, and records the guitar and bass via computer. He presents his idea to the other members as a finished work. Meshuggah typically adheres to Hagström's general idea and rarely changes the song afterwards. Hagström explains that each member has an idea of what the others are doing conceptually, and nobody thinks exclusively in terms of a particular instrument. Kidman doesn't play guitar in the band anymore, but he is involved in writing riffs.
Except for when Hagström needs a soloist, he and Thordendal rarely record together. Both play guitar and bass while composing. Haake says about his songwriting, "Sometimes I'll sample guitar parts, cut them up, pitch-shift and tweak them until I've built the riffs I want, just for demoing purposes. But most of the time I'll just present the drums, and explain my ideas for the rest of the song, sing some riffs."
Approximately once a year, Haake writes most of the band's lyrics, with the exception of finished tracks. His lyrical inspirations are derived from books and films. Although Meshuggah does not record concept albums, the band prefers strong conceptual underpinnings in the background.
Wow, I can't imagine writing like that with the kind of material they come up with. Mega props to them.