More than 5000 words are generated from "bhu", but only about 150 like भवति or भवेत are actually used in the corpus (wikipedia/source)
https://gist.github.com/shantanuo/218d3f1b392a49c4b1b9bc6a1cf9423b
https://gist.github.com/shantanuo/10d148bfaeec2387b855d8878c5c3a9b
Those are mostly "sandhi" words like हविर्भवति or लघुर्भवति
Assuming 4 words are usually used in a sandhi and assuming there are 10,000 base words then I don't know how to write this number.
10000 * 10000 * 10000 * 10000
I do not think hunspell can handle that.
German Language is close to Sanskrit when it comes to sandhi. How are they doing this?