Good question! With WikiSource that indeed might be a bit more complicated. Does https://en.m.wikisource.org/wiki/Adventures_in_Contentment/I and https://en.m.wikisource.org/wiki/Adventures_in_Contentment/II count as different articles? I didn’t check the dump, but I’m fairly sure those would be two different entities in there, same as two completely different articles on Wikipedia. If that wouldn’t be okay we’d need to have additional checks in the Sentence Extractor to consider the URL and only look at the base path for an article and ignore anything else after it, even if it’s a different URL.
@Oymate as a side question, have you tried out the Wikipedia extraction for bn? Does that work nicely with the non-latin script?