[Captain Kwok]

I always add shipset images to the default race directory and any default EMP files to the default empires directory. Mod specific AIs and EMP files go to in the corresponding mod directories.

Random AIs are generated by the presence of AI files with that race, or the shipset with the default AI files if custom ones aren't present. EMP files are not used to create random empires...

If a mod changes the game enough for the AI, the maker should have included at least default AI files that can function with the mod that random empires will be generated with. If none exist, the game will attempt to use the stock AI files which might result in non-functional AIs.

If you are using a mod and want a particular shipset to be used, copy the race to the corresponding mod race directory and add AI files that are compatible with that mod. You do not need to copy the images, since the game can use the images for that race from your default directory.