Yup,Godfather 111 was based on some truth as it was rumored the Pope was murdered-poisoned.
Godfather 3 has a LOT of messages in it, especially as it pertains to the connection between “The Family” and the Roman Catholic Church. You need to realize the the RCC is just a replacement for the Roman Legions to maintain control of the Realm and use it occasionally as “The Force” to make sure others fell into line or lose their souls.
In Godfather 3 the “Bank of Rome” which was formed in the 1940’s is merely a projection of the accumulated wealth of the RCC and in the movie was caught poorly investing in some “investments” and getting caught short. Very much in alignment with some stories out recently about shenanigans involving the RCC and other adventures, including bringing in “immigrants” they would sponsor who wee raised Catholic and assumed to share the new found providence and fill the seats