Upon looking at the assembled miniatures of Khornates and Sigmarines, I believe that the Age of Sigmar starter box has a great value, and the rules are free. However, the latter are seriously flawed for longbeard veteran players, by not having point values, nor army organization chart. Some groups made attempts to invent their own house-rules, but they always will be tainted by local impact and lack of broader acceptance. Another option is using well-comped rules of Warhammer 8th edition, but the "well-comped" term is quite crucial and goes into the same category as above mentioned modifications of Age of Sigmar.
So, maybe it is the time to drop Warhammer rules altogether and try something different for our precious 28-mm fantasy miniatures. Below are just few propositions, I'm sure many more can be found ... the point is to encourage you for searching a system fitting your taste.
Kings of War 2nd edition by Mantic (free download)
One page rules (for fantasy, sci-fi and historical)
Shadow Storm aka Fantasy Hail Caesar PDF (adyswargamesden.com)
The Shattered Crown: The Fantasy War Game Reinvigorated (KS project)