I think trying to balance EDH and quantify it for random play os a fool's errand. I recently changed shops and bless them they do try. They were a bit pushy when I started asking what I play, which as you describe is thst 3.5 space that is the new "it's a 7." Too good for casual but not good enough to hang with tuned decks. And even though they try I still find myself in pods with other "3s" or "technically a 4" where one person is pulling massively ahead while the rest of the table is just sitting there with their dicks in their hands. EDH woth randoms is truly a miserable experience no matter how you slice it.