I believe shortly after this list came out one of the mods came on and said that if you wanted to classify them into mid, low, high, tiers etc, they classified which were which, and iirc E was low tier, B was high tier, A was top tier, C was mid tier but borderline high, D was low-mid tier (sameas C, a borderline), G was bottom tier, and I'm pretty sure (but not completely sure) that F was low. I *think* that's how it went, and how that mod said it would be ideal to view it as, but you'd have to ask them I suppose.
The exact same sentence is also applicable to Little mac though.
See, I say Wario is the worst low tier for sheik to fight for a multitude of reasons, one of those being actual sets between top players of the characters that show it can be a rough patch for sheik (and yeah I know gluto's super good and that kinda carries wario here a lil bit etc etc). But looking for sets for mac vs sheik.....it's a little rough. Sol apparently has beaten k9, but k9 also plays diddy as well as sheik, and I can't find the set on YT. Nothing on Alphicans, and while Vash has beaten Nietono and Edge, Edge's set has him playing Diddy. If any of the Japanese macs have a win on a sheik then either it isn't listed or those macs don't have a page on the smash wiki so I have no real way of easily seeing what wins they have (bt yamato and // don't have pages, Yaminabe's wins are "Filip and several other strong players").
So whereas You can easily find Gluto fighting sheiks, a quick search of the top macs shows almost nothing for the matchup, thus I have a very hard time believing mac is as good against sheik as you say he is.