I've just spent the last 3 days creating a new set of pages to look at all the best publishers and designers. The rankings are determined by looking at the game ranks of the games in each publisher's or designers catelog of games to determine their placement.
The minimum requirement to become ranked was at minimum 10 ranked games for a publisher and 5 ranked games for a designer.
I'm still adjusting the metrics and wanting to be able to represent more information but the pages are live under the games drop down! Let me know what you think.
Popular Publishers Page: https://www.boardgameatlas.com/publishers
Popular Designers Page: https://www.boardgameatlas.com/designers