I know what you mean.
But Oden is also 2 zoros tall but, for some reason, his blades are regular sized now.
I REALLY dread to use Oden as parameter when he is clearly a product of Oda's self japanese wankness.
I could say Zoro outdid him by mastering Emma in just a few weeks, or that, but I fear that in doing so, Oda is gonna wake up one day and retcon Oden to say ame no habakiri is a black blade and Oden did it while fucking Toki, by also turning his dick Black.