While it's not exactly easy to counter Cawmodore, checking it is a lot easier than most think it is. Its checks are pretty omnipresent and have a wide range of uses; Cyclohm, of course, is rather common, Talonflame can revenge kill easily, and choice-scarf Waters and Fires like Mollux, Volkraken, Keldeo, and Heatran are also widely used as well and have a ton of utility outside of this role. Cawmodore is the main reason you use these, but Cawmodore has so little to actually hurt its checks, relying entirely on its teammates to wear them down. Cawmodore is dead weight until these checks are gone, because it's pitifully weak until it can set up, and all of these threats prevent it from setting up at all. Not to mention that if Cawmodore takes even one attack, like a Knock Off from Colossoil, or an Aura Sphere from Tomohawk, then Cawmodore is basically worthless, so you have to play as if you're down an entire Pokemon until Cawmodore can safely get in AND sweep past its checks.I do agree that Zard X and Scizor have better setup opportunities and are less reliant on team support, however I think cawmodore hits the criteria of S rank very well. "The best of the best. Reserved for Pokemon who shape and define the CAP metagame and are a clear-cut above the rest. These Pokemon are typically very powerful offensive threats that are difficult to prepare for."
It's undeniable that Cawmodore has one of, if not the biggest effects on teambuilding. Checking cawmodore isn't very simple and you don't just slap on a Cawmodore check and say done. To reliably check Cawmodore you have to normally dedicate a fair bit of your teams resources to checking it as it's such a powerful pokemon once it sets up, because of this it's more common to go out of your way and start putting checks on your team for Cawmodore rather than for Mega sciz and Zard X. Not only this, I think checking Zard X and Mega Scizor are so much more easier than checking Cawmodore. Another thing about Cawmodore is using some of it's checks normally guarantee a kill for the Cawmodore user as most of it's checks are 2hko'd with the slightest amount of prior damage which is normally easily achieved with the omnipresent Stealth Rocks. An example of this is I can keep forcing out your Cyclohm by using my Colossoil making you lose momentum and get weakened so it's either you keep switching or I set up and kill something that game and you send in your Cyclohm after the kill to kill me. Not sure if I explained what I wanted to well but lol.
If I did, I think Cawmodore is more than eligible for S Rank.
Yes, Cawmodore warps teambuilding, but not only do current S-ranks Tomohawk and Aurumoth do that even more, but Cawmodore's checks and counters are common, useful, and completely hard-stops to any Cawmodore sweep. I repeat what I said above here:
To be an S rank, you need to be the best of the best. The best in the CAP meta can provide support, offense, defense, and even sweeping, all in the same package. Cawmodore has no defensive and supportive qualities, and in fact /requires/ tons of team support to function at the same level as an Aurumoth, or a Clefable.
While it's much easier to stop a Mega Scizor (It's not easy to stop Char-X, at all), Mega Scizor and Char-X also provide a large defensive boost to the team in addition to a sweeper, and Scizor can also provide very easy pivoting as well.