At the time of Revolver and before (and maybe even after) the Beatles mostly left the mixing to others.
Even though I listened to the original stereo mixes for years, I mostly love Giles' remixes of the 1967-1968 material, and I bet the Beatles would, too. He does things like separating instruments or voices that were originally mixed together so you can hear the timbre and lines of each more clearly, and it adds power to a song like "Birthday" when the guitars are hard panned rather than sharing the same channel.
I forget about audiophile notions of hearing musicians in a space when I listen to most rock music from this period. I just accept that the mix is a work of art in itself. However, I don't like it when a drum set is panned unrealistically wide--a problem even in newer jazz recordings as well as classic rock recordings.