some people are idiots and dont read my full post.
I stated that they werent called emperors probably, plus gol D. rogers was not king based on his power, because Whitebeard matched him in a fight. Gol D. Roger was only considred the king because he had a ship that was able to make it wround the entire grand line and also allegedly had the most money.
Ranks exsisted back then too, its like saying back in cavemen time people didnt have ranks because they didnt live in united countries,
thats really bs people still had tribes, and just like that because piracy wasnt so big before roger doesnt mean there were no strong pirates with a classic ranking between them
Nowhere in the world can you find an organization or body of men and women living together without some sort of rankings. Even in families we have rankings.
Although they might not have been called emperors some sort of ranking system exsisted back then