Sure, the combined group of every single Arceus type is uncounterable by 1 poke (no shit), but a good team will be able to beat any Arceus set regardless. Since this thread categorizes Arceus by type, your statement "Definitely but arceus as a whole cannot be countered/checked thus keeping its place in S rank." has literally no base if you are applying it to EVERY Arceus form, since every Arceus form is not considered S rank: only specific forms are. Unfortunately, you are still wrong either way. Arceus can run a move to bypass a check but it means it will be checked by something else. Example: Arceus Fight with Stone Edge beats Ho-Oh yet loses to Giratina-O.I said arceus as a whole is uncounterable. Arceus can run some unorthodox move to bypass said counter/check. Arceus has an easier time sweeping late game due to its access to priority that other mons can't hope to compete with. I would argue about how you're wrong in that arceus normal provides no synergy but that would involve blitzlefan coming in here and bitching at me which I want to avoid.
This is why I avoid this thread because of the blatant, unchecked stupidity that seems to run rampant here.