- I want a complete list
- I want to know if there is an article in a language on a Wikipedia for the items on the list
The first requirement excludes categories.
The second requirement is provided to some extend by categories. In this case I used information from the English language Wikipedia. There was an article on the subject as well and it contained a list and this list contained items that were not in the category. I read many of the articles to add statements on these persons and based on the articles I had to conclude that some of the category items and list items were wrong.
All this is to be expected; Wikipedia does not claim to be 100% correct. It is for the people working on the content to refine and improve the content. The funny thing is that by reading articles I found candidates for other “categories”.
To get a more complete list, you can iterate the process on other Wikipedias. In addition you can add items to Wikidata based on “external” information. It takes some effort and, in a perfect world you would be aware of any items that are already known in Wikidata.
A list that is compiled in this way is superior to what categories offer; you would have red links in many places but you can provide information using info-boxes using the Wikidata statements.