This discussion reminds me of one of my 'creative' moments. I was under the impression that the new code language made my otherwise legal solution forbidden.
It was a small house, a complete rewire. Construction was solid masonry. Fortunately, there was an attic.
Even so, the large EMT (not sure of the size)I ran out the side of the outside panel, up the wall, and into the attic was pretty tight. So, to reduce my wire fill, I placed a can in the attic and mounted some terminal strips. I landed my grounds on one strip, and my neutrals on another. I did run a #10 ground wire (redundant to the conduit) and, I believe, a #6 neutral (the largest circuit was 20-amp, and circuits were split between legs) from the can to the panel. Thus, that pipe had many 'hot' wires, but only one ground and one neutral.
It was an exceptional situation, and I have not used this method again. Under the current code, I am clearly not allowed to do this.