Primebeard vs Roger says it all.
The ratio between strength and haki changes drastically with top notch CoA control. It's imo to a point where strength becomes totally insignificant. Each of them seemingly could have bust up that island. Shanks and Mihawk's duels shook the grandline,.. It's what they said.
That's obviously nowhere near comparable to all the other advanced CoA feats we have seen utill now.
Luffy and his "tree punch" for example, seems to be the near the minimum, totally amateurish in comparison.
An indicator for a higher amount of haki, seems to be those tendrils on swords. Imo Oda will also visualize post Enma Zoro's high end moves by adding much greater tendrils to his blades.
Later on Luffy might have big haki "clouds" around his fists.
But yeah, going from what we have seen from Zoro or Raisin or other characters who did not even have small tendrils at all and just hardened weapons, it's all absolute child's play compared to Roger's and WB's haki game.
They prolly did, what Enma did, but w/o going into drawback territory (arm crippling). Enma prolly went to that 120%.
Additionally their overflowing haki seemed to be focused, completely attached to their weapons and it did not simply flew off their weapons like it seemed to happen within the Enma scene.
Interesting detail, most guys also have their hands or the handle of their weapon covered. Seems to be a waste tho.
In Roger's and WB's case not even the handle was clad in haki. They prolly pumped the complete - drawback less- 100% into their attacks.
And when it's about those, the ratio imo could easily be around 95 (haki) to 5 (strength). That would also explain how he casuslly can send Oden flying across a freakin island.
Tho logically it should drain their haki tank much more than less used haki, so their casual haki game might not necessarily be on that kinda lvl. Those were probably more like high end advCoA lvl2 moves.
Put into perspective:
Luffy with his novice use could have, going by Hyo's words, deflected base BM's slap already.
How much of a strength boost would he need to replicate the same with just Hardening? A big one, that's clear. Perhaps one of the stronger G3 attacks would be enough.
And his moves seem to be "<<<<<<<" to Roger's from what I can tell.
Tomorrow I wanted to create a thread about this. I guess things happen :D