Tbh, SKA is just from one user and seriously, there isn't even much basis to it. Meanwhile ZKK was supported by fan theories and a huge amount of Zoro fans who argued for that for several years and defending the theory until the very end.
Now, it'd be different if SKA has the same kind of conditions like ZKK, then it's definitely worse.
But looking at these theories individually, ZKK had better "hints".