Dudes. Chill pills all around. We're all friends here, right? Right.
Realism isn't really much of a concern for me in terms of specific sizes for a region. It takes however long I need it to take to get somewhere. I mostly go off of the games in terms of a city's relative size, but I'll add in whatever I feel necessary. Towns obviously don't consist of only three or four houses, after all, and big cities will have a lot more than just personal homes and one or two areas of interest. Sometimes I'll add in additional towns or cities (I once had a fake town along the coast of the bay between Vermillion City and Fuchsia City called Navy Port), but since I don't have a single continuity between all of my pokemon stories, they're usually one-off things. I might reference real-world places or events, but I tend to keep it ambiguous as to where the regions are because, frankly, it usually won't matter whether or not the pokeworld is a series of island continents suspiciously similar to some regions in Japan, the actual regions inside Japan, or what language anyone speaks. Writing another language is fecking difficult because you've got to be sure you're doing it correctly, and it quickly becomes nothing more than a pain in the ass. The characters could very well be speaking another language, but the writer will be writing in English anyway (at least here), so there's translation convention at work.