I want to draw out the Parallels here first.
First Parallel,
Second Parallel ,
Third Parallel, Using Conqueror Coating. Which is crude and clumsy. First time usage or getting hang of it.
Now if you notice properly.
the third Parallel. , both zoro , luffy unlocked advanced conqueror coating.
but Focus at their lightening.
Luffy - Black and Red
Zoro- Black and Green
which Kaidou considered Crude and Clumsy.
now the question is what kaidou don't consider crude and clumsy?
if you look at any conqueror coated attack kaidou has made. They all are Purple. There's no black color in it.
all the top tier shown to have split skies have used one uniformly colored Conqueror attacks. There's no black in it.
which brings me to the
fourth Parallel,
Sadly , I can't compare further.
There's no officially colored volume after 102. Chatper 1035.
We have seen of luffy fighting in 1036. So we have to wait for Next Batch release.
Until then , Until Zoro Lightening Starts to look like this
He might not split skies until then.
Maybe in Egghead he already used Pure green Haki. But we gotta wait till volume 110 release. Which will take fuckin 6-10 years.
And I'm also not saying this Currently Zodo haki is weaker. But More he fights better he gets.
Problem is , Kaidou won , king lost. Zoro growth stunted at that moment. More he utilises it better he gets. So next fight is the chance where zoro acrually uses pure green Haki.
Why ? Because to follow the Parallels.
Zoro permanently scarring Lucci like oden did to Kaidou with his first Advanced Conqueror Strike.