Correct
Simulation accuracy, from lowest to highest:
1. Not loaded
2. View Only
3. Playable without details
4. Playable with full details
For my saves-
I put every league as playable. I put full details including cups and all leagues for whatever country I'm playing in. I put full detail for all Continental and International tournaments. Lastly, I put full details for only the top flight of the top countries
Try not to add or remove leagues mid save, adjust the detail level if it starts running too slow