It would be crazy to expect people to understand weird metaphors (or similes)
The question is, would it be crazy like a limp, soggy rug - or crazy like the steel manacles I'm using to keep my old writing teacher chained to the wall in the basement?
The advantage of using unusual metaphorical language is that it can shake up your reader in an unexpected way, backing up the car of your narration onto their brain's foot. Some readers will be pinned in place by the weight of your creativity. However, others do not like this sort of thing at all, and may toss aside your car, er, book...and walk away. Well, limp away.
If your objective is to be memorable, albeit controversial, then unusual comparisons are a great tool. I balk at giving countenance to "illogical" metaphors, however. When you draw some kind of comparison, or whatever, there's an expectation that it will mean something. In pure poetry, the thing you intend to communicate may not be the direct, literal meaning of your words - so if your clouds are soaring in the sky like angry horses, you may be trying to lead your reader to think of the size and power of horses, of uncontained anger, or even of the violence you would expect from an angry horse. Clouds rolling across the sky, given the right mood of the person observing them, may indeed soar overhead like angry horses. Or maybe the thunder from the black storm on the horizon tramples on your eardrum like angry horses... But if I'm to appreciate your creativity, I'd better not have to guess too hard at what exactly you're trying to evoke. You've got to include enough cues that the connection is fairly clear, whether the connection is to a sound, an emotional state, or whatever.
"A woman needs a man like a fish needs a bicycle" is a famous example of an unexpected and arresting twist - but nobody is left scratching their heads about what the author meant. (Maybe clawing at their eyes, but what can you do?)
*Note: I don't have a basement. And I have no idea what happened to my old writing teacher. Cross my heart and hope to make a killing on the stock market.