I will write my comments on the maps.
1. The Russian language is not divided into Novgorodian and Russian dialects but into Northern and Central dialects of the Russian language. Therefore, it is correct to write "Northern Russian" and "Central Russian."
Names for dialects
2. The Ruthenian language spread far to the east. This happened in the 16th century when Orthodox Christians in the Polish-Lithuanian Commonwealth faced persecution, and many moved east to the Russian Tsardom. Back in the 14th century, the Ruthenian language was spoken further west. There’s also a debate about Ukrainian and Belarusian dialects because both Ukraine and Belarus consider this a single language but argue over the name, calling it either Old Ukrainian or Old Belarusian, and denying that it had dialects.
Real border between Ruthenian and Russian in 14 century.
3. Regarding the Ruthenian language, this name might suit Western Europe, but it is a Latin exonym (a name used in a foreign language that differs from the native term). In Russian, this language is called "Western Russian" because it shares many features with the Russian language. Ukraine and Belarus argue about its name, calling it either Old Ukrainian or Old Belarusian. In the Grand Duchy of Lithuania, it was referred to as "Lithuanian-Russian," and in Poland as "Ruski" (with one "s," Język ruski).
Here’s a comparison of how the names of the Western Russian/Ruthenian/Lithuanian-Russian, Old Russian (14th century, referred to as "Russian" in the game), modern Russian, Ukrainian, and Belarusian languages were written in their respective eras:
- "рꙋскй ѧзыкь" (Western Russian/Ruthenian/Lithuanian-Russian)
- "рѹсьскъ ꙗзыкъ" (Old Russian in the 14th century)
- "русский язык" (Modern Russian)
- "українська мова" (Ukrainian)
- "білоруська мова" (Belarusian)
The Polish name "рꙋскй" ("Ruski") is the closest to the endonym (the term used by native speakers). Therefore, at least for the Russian localization, it would be preferable to use a name that was historically used by the language's speakers rather than a Western-derived term.
Source: "Ruthenia (Lithuania-Rus), in Europe: A Literary History, 1348—1418." Edited by David Wallace. Oxford University Press, 2016, Volume 2.
4. Again, on the topic of exonyms and endonyms, the term "Moscovy" is another Polish exonym derived from the Latin "Moscovia," which has no connection to the name used by the local population. The state was called "The Grand Duchy of Moscow", so it would be preferable to see this name.
You correctly use the name for Poland but could have also used the exonym "Varsovia" (from Warsaw) for Poland, as it was called in Western Europe, or "Kiovia" for Kyiv. Similarly, you use "Moskva" on the markets map, which is already the Russian name and not "Moscovy."
Therefore, it would be accurate to use "Grand Duchy of Moscow," and the people should be referred to as "Moscowians," not "Moscovites."
5. Province and country names appear to be unfinished dynamic names. For example, provinces in modern-day Ukraine have modern Ukrainian names and spellings that only appeared in the 18th century, while the map is set in the 14th century. Additionally, some province names are written in Russian or Belarusian. For instance, the province "Mstsislaw" is written in Belarusian, while the country is named "Mstislavl" in Russian. The name "Mstsislaw" appeared in the 15th–16th centuries after these territories were annexed by the Polish-Lithuanian Commonwealth. This suggests that the naming conventions do not align with the historical period depicted on the map.