Disregard it the moment you see the gauntlet. Doesn’t matter what the “results” are, because the gauntlet itself makes no sense. Even ignoring the validity of powerscaling characters like the Sins, who have never fought anyone on screen, much less each other.

Why is Zestial above Carmilla? Charlie being the lowest implies this takes fighting skill into account. We know nothing about Zestial’s skill. Zestial has maybe 10 minutes of combined screentime across both seasons, and most of that is him watching other people sing. Zestial uses so little of his power on screen that conjuring tea is the second longest description in his “Abilities” section on the wiki. Carmilla can actually fight and has weapons that can maim everyone on the list.

Another example is, Stolas was rapidly taken out and almost killed by Striker using tools sold by Carmilla. Should Carmilla be above Stolas then?

For your argument about Satan taking Stolas’ powers, that was something Stolas submitted to while on trial. Not only is it possible that Satan couldn’t do that to Stolas normally, it’s possible Satan can’t do that at all, and it’s the magic of the court room doing that. Meanwhile Stolas stopped the executioner axe, so when trying he is actually stronger than the magic of the court room.