Sorry Secret God but I have to agree with everything Camus has said
I can't quote directly but I have heard Neil talk in interviews a few times about Nick's "fiddly" basslines in comparison to the more direct grooves played by Sebastian Steinberg, etc. (note: I don't think Neil was having a go at Nick, just stating the differences in style).
Nick is a very distinctive bass player and his style is easily recognisable and as Camus has pointed out, I don't think Neil could play that way. He's certainly never shown any evidence of it when he has played bass.
I think what made CH so special was the fact they were very much a band . You can hear it on the recordings and you could hear it live. Just because the songwriting credits weren't split equally doesn't mean they were less of a band than anyone else. The Beatles are most people's idea of the ultimate pop/rock band even though most of their work was credited to Lennon/McCartney. You don't hear many people claim George or Ringo weren't a big part of what made that band.
If you look at most bands over the years they usually have one (or two) members who bring the songs to the table and then the rest of the band will add their parts and shape those songs till they become something unique to the band as a whole. The Rolling Stones, The Who, Led Zeppelin, Pink Floyd, The Smiths, Oasis, Travis, etc all work this way. Then you have bands such as U2, REM, Coldplay and Radiohead where they jam in the studio to come up with songs or members come with half-finished pieces which are completed as a band. Or they have an agreement that the songwriting credits are split equally even if one member has solely written the song.
Back to CH, I would imagine often Neil would hear a drum sound or bassline in his head for his songs and would have to convey that to Nick and Paul. Most likely it'd be distorted in the translation or taken in another direction completely. Other times it'd be solely left to their imagination to deliver the part. That's what makes bands so interesting.