i don't know as this is the first time I'm aware of any limit. That's why would like to know if there's a way to delete specific 'logo' data and not all.
In game there is a way to delete logos individually but that would take time and also i wouldn't know which ones to delete. With so many more teams being made we will need loads more space for logos so deleting just a few will not work. I did check for duplicates but i cannot find any. Normally when i download a team or stadium i press yes on replace logo if it already exists. This can become a big issue i feel as the game depends so much on custom logos!