I love both songs. If you had asked me, I would have said (from memory) that "Pyramid Song" is syncopated. I think there is some kind of magic involved.

When I was studying poetry in high school, my teachers emphasized the beat in a very mechanical way. Iambic tetrameter was ta-DUM ta-DUM ta-DUM ta-DUM. So any two lines of iambic tetrameter would (theoretically) sound the same. Of course "I wandered lonely as a cloud" (Wordsworth) and "The pig lay on a barrow dead" (Ted Hughes) are quite different, and to read them in the same mechanical way does an injustice to both poems.

There are subtle gradations of rhythm (tiny pauses, lengthenings, shortenings) and emphasis, to say nothing of differences in tone and pitch that make any supposedly regular line slightly irregular and distinctive, and this is what separates art from arithmetic. Radiohead are geniuses at incorporating artfulness without bludgeoning the listener with their art.