So there's no difference between grabbing the latest update from NUS vs installing the Venom update then letting the game update itself on Wii U?
Then now it's possible/safe to delete de initial update and let the game update by itself?
I can't say if its safe for sure but i'd think so. In their NFO VENOM even suggested to get the update straight from your console (as a possibility) and i'd assume they know what they are suggesting here