Thanks for the clarification, so long as those cases are clearly marked on the submissions page, that seems like a good solution.
I also don't mean to harp on the Summerlands, as I don't think they had any malicious intent and it was a case of the rules not being clear beforehand, but I also wanted to point out it's not just art assets they're working on, but the whole game, code and script and all. I only want to point this out so that next time there can be clear rules (regardless of what the rules end up being), as this isn't the first time I've seen a similar mix up when a jam doesn't state the rules on the main page. Some people haven't been jamming since forever and really are unsure what is considered 'traditional' for a jam, and with so many new jams with different rules, it's better to just put it all in writing from the start so there's no confusion.
Again, nothing against a more relaxed jam if that's what you guys would like to do in the future! Just asking for clearer rules from the get-go, not necessarily a stricter jam.