On English to Russian:
10000 most common - capped at 10000 sentences
20000 most common - capped at 10000 sentences (this is fine if it covers all the 10000 newest words above the 10000)
50000 most common - capped at 10000 sentences ???
The 50000 most common is weird because this would indicate there are 30000 words to have sentences but the 10000 limit would only cover 1/3 of them for clozes.
Now if that’s all there is available uniquely in the 50000 that just is what its but it just seems odd math wise looking at it.