This is how I interprete it, when they became campione they receive an insane amount of divine energy at least the same as a high heretic god (And you want more
). And that is their limit, because as a former human that is their limit, they can use more transforming into or using avatars, allowing them to surpass anything their former selves as humans allowed them to use. And in the midst of battle they learn their optimal forms when using those authorities allowing them to use little to accomplish much. Of course it doesnt matter how you put it Voban was a beast he was nonchalantly handling the goat, if it wasnt by the sword Godou would have lost Goat or not, what truly tired Voban was the ability to revive himself from ashes in seconds. The minimum time of the Ram is 2 hours, and he did it in seconds from ashes, I dont know if even the Ram could revive Godou from ashes and just how much time it would take.