I fully support any Pokemon that puts a complete stop to Moltres. HP Grass does 38-44%, which could be a problem if switching in on Rocks, but Fire Blast does only 24-28%. A fucking Magcargo is 4HKOed by Moltres Fire Blast without any SpD EVs at all.
It's not that reliable of a Swellow check due to SR weakness. Facade does 26-31%, so if Magcargo has taken SR damage once before and switches in again, it's a 2HKO. Say, for example, Swellow comes in and U-turns to Milotic as Magcargo switches in. Then next time Magcargo switches in it's 2hkoed by Facade. It's probably good enough, but Swellow is never ever ever breaking through Rhyperior/Steelix/Regirock so it's not great by comparison. (Plus Swellow can't be burned, which is one of Magcargo's biggest selling points)
As for Scyther, SD Brick Break hurts it a ton. +2 Brick Break does 79-94%, almost a guaranteed OHKO with SR. It does great against CB Scyther, although Brick Break is a 2HKO with Rocks (45-53%). Its main advantage here is that it's the only Pokemon that can pinish Scyther for U-turn spam due to the Burn chance. On the other hand, if Scyther keeps U-turning to Milotic it keeps Rocks of the field, so that's a downside.
So there's my damage calculation-obsessed side to it. Basically, if you keep SR off the field, it can perform a pretty useful niche, but there are probably better things to use.
Against my current team, I can see it being sort of annoying because it gets free switches on two of my Pokemon, and my team hates being burned. But half OHKOs it and the last Pokemon isn't bothered by it at all.