Is King of Beggars the most powerful character in the Witcher universe?

A famous phrase by a wise Elven commander, Iorveth, is : 'King or beggar, what's the difference? One d'hoine less' . This implies that there is no difference between a king or a beggar, so king=beggar. This means king of beggars is actually king of kings (or beggar of beggars,but there wouldn't be someone kissing his hand on his card art if he was beggar of beggars ). King of kings is like the most powerful king, which means he is more powerful than Emhyr and Radovid, 2 very powerful rulers, which means King of Beggars could actually be the most powerful character in witcher universe during Witcher 3 (post-witch hunt).

Thoughts?