There are 43 custom stable logos in currently, they're all under zz_Stable__ double underscore while real stables have one. The biggest issue is finding logos to use for new stables so if you have any suggestions please let me know and they can be made. Currently they're all from Destiny emblems or Esports orgs.
I started working on it so maybe I'll finish it eventually. RWC is setup with future workers to use images from Sabin's free pic pack so I'll need to make sure everything matches and they're not grouped together ethnically so I can't e.g. go through a Japanese rugby team and easily do 30 images. Grabbing the images from various sports is easy, it's just tedious to jump around so I put it off and then forget about it for several months until someone bring it back up.