I actually like the idea of Emperor being a bit of a fuck up, rushing for no reason, attacking all xenos even when it is disadvantageous in the long term, handling many primarchs with care some caveman would handle a piece of bone, utterly misunderstanding Chaos Gods, figuring they were powered completely by faith instead of their main source being emotions etc.
It shows that despite how he viewed himself as a paragon of manking, above their petty squabbles, he was still ultimately human, with all the flaws and hubris that entails, and that being his downfall, instead of whatever he's doing in Horus Heresy, think he sorta orchestrated it or something?