I think it's about the sound. Something with "che-ia", something with "Swen"...

Like, if you really don't know about the world, or the regions of aforementioned countries, which could very well be, then I see the possibility.

When I revisit the words I kept confusing when I first started learning German, I'm like, did I have mental problems or what!? :)

> Czechia and Chechenya

I couldn't find it but last week I read a twitter thread about a software company in Czechia that had gotten some crazy request for documentation because they had been flagged as being in Chechnya

> I can understand mixing up Slovakia and Slovenia

Don't forget the historic regions of Slavonia and Slavinia. While neither of those two is an independent country at the moment, you never know what's going to happen in Eastern Europe.

> I have no idea how that can be a thing.

Yeah even that is a stretch. But at least you can pronounce them incorrectly to sound similar. You cannot do that with Sweden and Switzerland.