Yes, hence Sword allows him to use all of that Haki in one attack, makin the attack much much stronger than he usually does.
It's like assuming Top tiers have bigger reserve of Haki , and they use considersble amount of it in their attacks, which is quite strong.
And Since High tiers n below have less Haki, there each attacks also has less Haki, hence are not as strong as Top tiers.
Bt Enma will Allow Zoro to use that all of the Haki in one or two attacks to produce the strongest slash, makin it much stronger, maybe even comparable to that of Top tiers.
Bt since Zoro doesn't have same reserves of Haki as Top Tiers, one or two attacks of this scale will leave his body sucked out like we saw in Panel or go Hakiless like Luffy does after G4 for few mins.
So it's the perfect PU to Injure Kaidou.