We have to be objective here with Enma. I trashed Zoro when people suggested he could do shit to Kaido, or his disappointing upper body physical strength display against King (Jozu would have laughed off King's attacks).
But Zoro here is objectively
nerfed. He's struggling to use Enma. This ordeal will make him stronger LONG TERM, but for the short term he is nerfed, especially if he is down to 1 sword as per spoilers.
If Zoro was in "normal" mode with Shusui, a fucking
black blade, he'd do much better against King. That's the sword of a "Sword God" who sliced dragons.
Until Zoro masters Enma, it is a clear nerf.