Hmmm, I'm not sure that I understand your question, and I doubt anyone can without you pointing-out some tracks and asking more specific questions...
In general, I suppose Nujabes and Shadow are similar in that they prefer "groovy," organic drum and percussion sounds, from diverse sources like soul/r&b and jazz. It sounds like Nujabes in particular used some very classic tracks from the jazz and soul genres (everything from Ahmad Jamal "Live at The Pershing" to Creed Taylor productions to Stax/Al Green type grooves) as the looping basis to build some pretty standard 90's "boom bap" beats. So they're using pre-recorded samples to make loops, then layering more (fairly organic, standard hip-hop sounding) drums on top of those loops, and layering additional samples and effect elements on to those. The original drums "sound like a kit" because they are/were; they were originally live drums played by a live drummer and recorded in a room with a band all at the same time. Vintage records that were made that way will sound like that. Same reason J. Dilla preferred those records.
Is that what you're looking for? If not, you need to get more specific!
GJ