But that isn't what's going on here (or anything like Dick's 1962, The Man in the High Castle). Instead, this more closely resembles another tradition, which includes "Mirror, Mirror" from Star Trek, and the Crime Syndicate of America (both 1960s again). In these, rather than a serious attempt at doing a what-if, you make history a mirror image in order to justify an evil version of the team, which each member having a malicious analogue. In "Mirror, Mirror", there was an Evil Captain Kirk, an Evil Spock, and suchforth. In the Crime Syndicate, a bunch of folks with the same powers and names were all villains instead, and decided to band together. Never mind what a remarkable coincidence it is that the ISS Enterprise happened to be at the Halkan homeworld at the same time as the USS Enterprise - that's completely besides the point, and is a misunderstanding of the genre of story being told here.
In this case we want an Evil version of Excalibur. Excalibur is very much a British team, and Britain's defining national identity myth - in the absence of any independence struggle - is the Second World War. By default the Evil version of any British superhero team will be a Nazi version. And that's what happens here. Hauptman England is fair enough: Captain Britain with a swastika. He's an English aristo, so frankly that's a natural fit (I like how the Internet hasn't quite realised that Hauptman England is very likely just an alt-Braddock). Reichsminister Moira MacTaggert makes sense, too. And Nightcrawler is German already! So he makes an excellent political officer. And who doesn't enjoy an evil Nightcrawler, eh? Evil Meggan is a bit difficult given her background, but the real problem is Kitty. Kitty Pryde is Jewish. Very Jewish. So, Earth-597 has an evil tortured ghost Kitty, bald and with a star of David tattooed on her forehead where the others have swastikas on their costumes. Worst. Idea. Ever.
Curiously, there's no Phoenix. Like the lack of Doctor in Inferno (Doctor Who, known for its genre-hopping, did this the first season it got a stable home base), perhaps this is because Rachel Summers is a time traveller, not bound by the laws of mirror universes. Can you imagine a Days of Future Past future for the Lightning Storm universe? I wouldn't know who to root for: the Sentinels or the Nazis.