@SMXLR8: Ok so heres a rough version of the order of super powers I think
1. The Four Emperors
They are all equal to Whitebeard apparently, who is city level plus in strength and Shanks was shown colliding equally in a fight with him, Kaidou and Big Ma'am dont have any showings of yet, but Black Beard is the strongest most likely especially with his ability to steal others DF fruits
2. Marine HQ
They have the admirals who by powerscaling have city level plus durability and high town busters although if Law is an island buster then I suspect both Admirals and Emperors are above that for it's unknown the full limits of both
This is much more varied power wise, especially since Buggy is in it :P But they're all pretty damn high
These are all pirates who are on level with Luffy, although Law has the greatest feat among them of course with his island slash. These guys are building their way to the top, and most likely will surpass Shichibukai and possibly admirals but how soon that will be is unknown.