Funnily enough, Victini has the better typing since it allows it to check things like Mewtwo. (which isn't exactly common so it's a nice niche) V-Create is also a giant nuke under the Sun and hits for the generally softer physical side of the metagame. Having stuff like U-turn adds to it's utility (although SR weakness is sad) and Bolt Strike is great for bulky waters. (the popularity of Sp.Def Ogre completely ruins Reshiram) It's not much better but it gives more excuses to be used on your team.
I agree that good teambuilders will have many options at their disposal to prevent Deo-S from lazily laying hazards early game but it is still very effective at this role. (one of the reasons Magic Coat is getting so popular) I'm personally not a big fan of it myself but I didn't want to not give it enough credit.
Magic coat does not stop sr, no idea why people think otherwise. At best it makes it so both sides have sr on both fields which is arguably still a win for the deo-s user.
I think that Deoxys-S should go down, preferably to Top B-Rank. Deoxys-S is not very good in the metagame since most opposing leads can beat it. Genesect can U-turn out and switch to a priority user (which are pretty common. Giratina_o can 2HKO it with shadow sneak. Ghostceus can bounce back its hazards with magic coat and bring it down to its sash with judgement. Custap forretress can use the combination of gyro ball and rapid spin to prevent it from doing anything and the list goes on and on. And unlike the aforementioned pokemon, Deoxys-S cannot function any other major role effectively. The only thing that keeps Deoxys-S in Top B-Rank is the dual screens set, which can allow a frail sweeper such as rayquaza to set up with ease.
Also, I'm confused why victini is top C-Rank while reshiram is mid C-Rank (not saying that reshiram is good, but it appears to be better than victini thanks to its better STAB combo and typing).
Sorry if I'm confusing, but its 1 am where I live so I am somewhat tired (not like you guys care).
Gene is outsped and loses a massive chunk of its life from fire punch/hp fire if not outright ohko'd from deo-s. Not even what I'd call an opposing lead since it loses so utterly. Ghostceus with magic coat? We're really reaching for straws here if you really think it can afford magic coat/judgment/recover/filler not to mention magic coat doesn't stop sr. Custap forry will never stop deo-s from getting at least one layer despite what poppy tried to hype it up to be. The only reliable way to stop deo-s from setting up hazards is scarfed rai. Everything else cannot stop deo-s from getting one layer, switching out and then potentially setting up more hazards mid/late gam.