Zoro never had huge chunks of his Haki forced out of his body into a specific blade the way it happend with Enma.
Looks, there's clearly a Haki related interaction that Zoro had with Enma that happened in a different manner than his other blades.
Enma is also the first of Zoro's blades that it's discussed to have been owned by someone who was on the path of turning it into a black blade.
None of your arguments dispute that the manner in which Zoro interacted with Enma could have fast tracked him on the concept of turning a blade into a black blade, or that said blade makes most sense to be Enma before any other, because of how it was discussed as a sword that Oden was on the path of turning black as something to keep in mind when Zoro received the sword and started his unique training with it.
Looks, there's clearly a Haki related interaction that Zoro had with Enma that happened in a different manner than his other blades.
Enma is also the first of Zoro's blades that it's discussed to have been owned by someone who was on the path of turning it into a black blade.
None of your arguments dispute that the manner in which Zoro interacted with Enma could have fast tracked him on the concept of turning a blade into a black blade, or that said blade makes most sense to be Enma before any other, because of how it was discussed as a sword that Oden was on the path of turning black as something to keep in mind when Zoro received the sword and started his unique training with it.