One doesn’t necesarily cancel out the other. While it is certainly true that Rick Priestley’s Hail Caesar is most closely ‘related’ to his earlier Warmaster and Warmaster Ancients rules, it is equally true that HC shares a number of core mechanics with both WFB and WAB, also co-written by Priestley. After all, we are discussing wargame rules writing, and not literal lineages or genetics.
"Ventosa viri restabit." ~ Harry Field