The dude is only properly featured in one canon chapter and he's got like 3 major hype movements in it.
Any top tier could have done the things he did.
It just seems hypocritical that Kid is somehow a fake rival of Luffy's whereas Shiki is considered a valid rival of Roger's. Despite never being portrayed to be on Roger's level.
Literally the only pirates who have that portrayal are Whitebeard and Xebec. Shiki was a minor rival, just like Kid and Law. Oda didn't even give him conqueror's haki.