That whole scene was weird. Doffy knew he would get wrecked but still attacked smoker. What did he think Kuzan would do just stand there? And then he didn't even engage him in battle. And that whole doffy got frozen doesn't indicate at all how close to he was to dying. Maybe kuzan held off to not kill him or doffy just broke out of it easily. Wouldn't read to much into it. Anyway kizaru would mid diff him at most likely.
It was really well done imo.
It managed to hype Doflamingo without making him or Kuzan look bad.
Doflamingo showed he wasn't going to simply take orders from anyone, so he stubbornly tried to finish Smoker off despite one of the top 10 strongest beings in One Piece standing behind him.
Kuzan showed how fast he was because he froze an entire stadium sized area before Mingo could even strike the guy he was directly ontop of.
But then Mingo moments later breaks out of the ice, and yet Oda draws him panting as to say it was easy but not all that easy. All this done when Kuzan looks extremely casual.
Then Doflamingo walks away but here is the thing, Doflamingo would walk away whether he was anywhere from Akainu level to Nami level.
Akainu level = 10 day fight while Law and Luffy are on the verge of ruining his entire business + shichibukai title
Nami level = Dies in less than a second.
So even if Doflamingo could beat Kuzan he would choose not to fight him because nobody in One Piece including Gol D Roger is beating Kuzan easily, at best it would take mingo 10 days and up to beat Kuzan. Him walking away tells us nothing about where he stands in the power scale. So him walking away manages to show respect for Kuzan's strength but at the same time takes nothing away from Doflamingo at all.
Later when Doflamingo leaves Kuzan starts hyping Doflamingo up by saying he is not like any other pirate and dealing with him will be Akainu's biggest task.
With an arc for Doflamingo coming up immediately it was important Oda doesn't make Doflamingo look weak but at the same time he couldn't just make an ex Marine Admiral take a fall in portrayal to hype Doflamingo. So it was actually very well done, effectively hyping Mingo before his arc while maintaining Kuzan in the pecking order. That scene was never supposed to be a negative for Mingo like people imply.