I appreciate the effort, I truly do, but I cannot play CK2 when the region placement is utterly wrong and immersion breaking. I'll try to reinstall without the SWMH and use the vanilla map.
If the names are the issue, you can potentially also play with SED (Speak English Dammit), which turns most SWMH names into the names that an English historian would use (instead of localized names). In the other direction, there are also some submods like More Cultural Names (MCN) that add a whole bunch of extra, culture-specific names, and I'd imagine that Moravian names for most places in the Carpathian Basin outside of the Slovakian part would be one of those things.
If region placement is the issue, there's unfortunately no good answer for you. During my sweep of Hungary's baronies for Frosty1, I replaced a lot of incorrectly placed and/or actually unimportant settlements in Slovakia with ones that were more correctly placed and/or more important ones (e.g. it's how Malacky ended up actually present in SWMH in the newer version). However, the administrative divisions of the region varied so wildly throughout CK2's timeperiod, and province borders being fixed in CK2, means that no matter which map you take, you're always going to get immersion breakage. SWMH's map is meant to be able to represent the organization of the Kingdom of Hungary in 1000 and in the early 1200's the best. Vanilla's map doesn't seem like it was built to represent any historical divisions well (heck, in early versions of the game, even the Danube flowed through completely wrong territory), but IMO, it seems to be best set up to represent the divisions in the late 1200's and early 1300's. Like I said, there are no good answers.
I am all in for including all ethnicities in the game, if it is historical. I was surprised that they were as far as Spisz(Spiš) and Abauj(Abov), for as long as I am aware, they live only in the easternmost districts of Slovakia, south-western Ukraine, south-eastern Poland and north-western Romania.
This is where we run up against the issue of only being able to have one culture per province, and a little bit of naming confusion in this case as well.
Let's go with the naming confusion first. Abaúj/Abov and Szepes/Spiš in SWMH are not exactly the same as Abaúj/Abov and Szepes/Spiš as you know them, i.e. the territories that were called that starting from around the 18th to 19th century (and firmly established in 1867). Abaúj especially constantly had its administrative borders redrawn throughout history (though they always included Abaújvár, and generally seemed to hover around the historical territories of the Aba clan/family, themselves most likely originally Khavars/Khabars), and Szepes didn't even really exist as its own administrative entity until after the last start date in CK2. But we still have to call those regions of the map something, and Szepes still needs to be separate because while it didn't exist as its own administrative entity, the territory it marks did change hands fairly often, so Abaúj and Szepes it is. Especially if you're looking at the 867 start date (i.e. before the Aba clan even arrived in the area sometime between 893 and 907), you should think of those provinces not as the settlements themselves, but as the territory they cover; Szepes isn't the settlements in the Szepes barony, it's the territory in which those settlements would take hold later in history.
Now, the one culture per province issue. The Rusyns are/were kind of dotted all over the place in that region, especially because in CK2's timeperiod, they weren't actually a unified Rusyn group, they were actually 4-5 of the many East Slavic groups that later, through the evolution of borders and politics, got grouped into their own, separate, "Rusyn" category by outsiders, which they then slowly adopted as their unified identity in place of their old, subregional identities. Here's a rough map of where those 4-5 subregional identities were present (from Encyclopaedia Britannica):
Of course, the only reason those specific subgroups were called their own, special, "Rusyn" label is because of 18th-20th century politics, so there's no real way to know which groups of Southwestern Rus' would have actually become "Rusyn" had history gone down a different path. Hence, my previous points about the problems with Rus' consisting of a continuum of different regional varieties in language and culture (and why I presume there was much debate about where Mr. Dovakhiin drew the borders for his Horvatsky / White Croat culture and de jure Kingdom in his submod).
If CK2 had a proper system for supporting cultural minorities, they'd have minorities in Máramaros and Borsod as well, and Moravians (and later some Saxons) would have minorities in Szepes, Borsod, and Abaúj (Zemplén is pretty much the only place that definitely was predominantly Rusyn); again, I'm talking about the specific SWMH provinces, i.e. the territory that provinces named as such represent, not the 19th century historical administrative divisions. But alas, we do not, so for every province, we have to decide to represent the entire population of the province as all one culture. So, based on that map (and some other maps that show roughly the same thing), I decided that the territory covered by the provinces of Szepes, Abaúj, and Zemplén in SWMH are majority Rusyn, and that is why they are Rus', even if that does at first sight seem to place Rusyns more West than they actually were.
