I think this is an onion with many layers.
If for example you're talking about all of the Daredevil original art ever created in human history, then ALL Frank Miller covers would be considered "A" or "god" tier.
But I'm sure some advanced collectors would consider some Miller DD covers to be "B" or "C" relative to other Miller DD or maybe just all other Miller material period.
So what does that make a really cool Scott McDaniel DD cover? In the eyes of an advanced collector who's calling some Miller covers a "C" it probably doesn't even rate.
But in reality it's probably in the top 10-20% of all published DD art ever, right?
It's similar to discussing what the greatest movies ever made. Awesome topic to discuss, and should be able to build some general consensus, but will never be definitive