Who's Who thought he could face a Calamity but he didn't actually back up his confidence. He gave Jimbei a decent fight but the difference between them became more apparent as it continued. Jimbei's bounty doesn’t change Who's Who performance especially since Who's Who was wanted for reasons other than strength and still only had 546 milliom compared to Queen's 1.33 billion. Plus Jimbei was a former Warlord that officially joined up with an Emperor crew as a Commander.
Overall, Queen has better feats and hype. Who's Who had decent hype but his opinion of himself wasn't consistent with reality and Luffy or any of the Calamities would've shown him what's what like Jimbei did. Not sure why Queen's being singled out to be honest.
