Can The Jockeys List Be Expanded? or can you only edit the current one?
Thanks

The jockeys list can be expanded.

Through trial and error, it's recommended to have at least 75 jockeys for a main game cou try and at most about 250/300. You'll be seeing mods up soon with SO7 jockeys available.

Is this the same for trainers? Because I always found that if you try making more trainers than 100 on so6 it didn't work

You can have more than 100 trainers. I had about 150-200. I recommend 100 because after that, many stables become too small, especially at the top.

My golden ratio has been ideally 100 trainers and 150 jockeys. Gives realistic stats, offers good diversity in trainers entering horses, and makes sure top trainers have large stables.