I have to say, I really like this idea. Not just because I run the Wart support-thread (
), but also because, by virtue of the story setup behind him and his appearances (after Super Mario Bros. 2, he fled to another dream-world to lie low for a while - this being Koholint Island from The Legend of Zelda: Link's Awakening), Wart actually has to exist in real-life, outside of the dream realms, the same as the characters he's fought do.
Wart hasn't been seen in real-life yet, and the idea that he'd be Sarasaland's equivalent to Bowser is a really charming one for that reason, and would nicely explain why he's been able to stay hidden, since Sarasaland is relatively unexplored.
I thought that Super Mario Land had it so that the enemies you encounter are her subjects, under Tatanga's hypnosis?
I'd really like to see this. Best of luck with it!