IMO the New 52 Legion was underrated. I liked who they were and their spot in Morrison's story... but I don't think that should have completely meant scrapping the Kirby stuff.
I think if anything, that is the one idea kept through the New 52 and to today distinctly from Byrne.
It was a piss take to introduce Brainiac from an unconventional angle (not just coming to Earth and trying to shrink stuff) and really, for all the things that could have been untouched, I think that's one of the better cases. All you would have to do is draw the android form instead of his natural Coluan body and it's exactly the same. Even if Superman had fought Brainiac before he could be skeptical that this man really has that consciousness stuck in his head.