Doflamingo made Law with a broken ope ope no mi who was competent against Kaidou and BM on the he roof with the same abilities....look like a toddler. He's the only high tier Oda was comfortable drawing breaking out of Kuzan's ice, and Oda drew him sitting ontop of Jozu like he was a footstool.
Not to mention he achieved awakening, and is a born conqueror, both things Marco and King are missing.
Let's pump the brakes...Doflamingo's portrayal is immaculate. The only thing holding him back is his underwhelming Dressrosa AP feats and underwhelming haki. Katakuri was an upgraded Mingo, if he didn't exist the portrayal argument was absolutely there for him.