I'm doing 25 leagues from 18 countries with a large DB. 64k players.
The goal with the setup is:
Playing a Swedish club.
Good game speed.
Finding mostly EU-newgens and I dont want to scroll through 10000 south americans in the scouting centre.
Loading my favourite EU country leagues, enough of them to have bids on my players and active transfer market.
Loading no non-EU leagues as leagues are what slows down the game the most, and non-EU clubs rarely bids on my players.
Loading only low divisions from my country to get more home-grown staff and newgens.
Loading only 2nd divisions from neighbouring countries. I prefer loading leagues from more countries instead of second divisions from the same few countries.
Loading custom database and check international players from my country. That adds 20 international players.
Feel free to give input on to thoughts!