No Nik-chin. Read properly. Enma draws out an excess amount of Haki from its user, but the user of course can still utilize that Haki in all of his weapons. That's why it was said Enma was the "only" sword capable of scarring Kaido, despite Oden using both swords to give him an X shaped scar.
Independently of how we define it, King of Hell is a mode using excess amounts of Haki. And Zoro used it to one shot a flameless King. That's not a basis you can use to claim Zoro's Haki is stronger than Shanks'.
Enma is thirsty for haki and a nasty sword for someone who hasn't "surpassed it".
It indeed draws out haki from the user who hasn't surpassed it.
However, in Zoro's case from the moment he released CoC, the sword has been "surpassed".
It no longer draws out any haki from the user because user is overwhelming it with more haki than it can handle.
For a sake of the example, lets use tons here and say that Enma draws out 1 ton of haki from the user.
Meanwhile, the user who has surpassed it, overwhelms it with 2 tons or more haki, virtually nullifying its special effect.
That is why all of Zoro's swords have the same amount of excess haki, Enma's abilities no longer takes the spotlight.
Also, Enma being the only sword capable of scarring Kaido is factually false due to X shaped scar.
King of Hell is a haki release state that surpasses the levels of Enma's ability.
Based on Zoro's Dragon Damnation, he is a better hakiman than Shanks based on his Divide Departure.
