It might be helpful if I disclosed by internal bias, hopes and perspective a bit better than I did in the original post here, which I'd hoped to keep short.
My view of DNA bloodline connection is what led me to originally make this post, and that perspective still stands, regardless of his wife Yoko Ono's excellent pedigree.
I must admit my own bias toward preferring to work to reach back for every member of our tree, and not settle for 'that's good enough,' but rather continue making every effort to dilligently press back further through ancestors where we collectively have the skills to do so.
I'm currently fairly skilled, for example, with tracing Scandinavian roots, which can be a bit nerve-wracking for those unaccustomed to the ever-changing last names. I'm therefore hoping that here at WikiTree there might just be somebody who can help us find out a bit more going back in time in John Lennon's own pedigree chart of bloodline relatives.
I've been doing just that on Marilyn Monroe's Norwegian side of her family, despite the fact that she is 'already connected to the big tree' here at WikiTree. I just keep getting a sense that it's sooo much better when we put as much of this collective jigsaw puzzle together as possible, and I have a sense that what we get out of these efforts is so incredibly worthwhile. :-)