Here are two interesting, very well made films which draw heavily from actuality in shaping their Drama:

The Last King of Scotland: https://www.imdb.com/title/tt0455590/

The Devil's Double: https://www.imdb.com/title/tt1270262/

The best choice I can offer is a bit less "grounded," but just as "true" in its implications: Beasts Of No Nation:

https://www.imdb.com/title/tt1365050/