P.S. After attempting to translate what the OP was talking about, it looks like he could have fixed his problem just by flipping one fan around. Yes sometimes from the factory they are backwards, sometimes from the factory they are plugged in backwards on the controller as well. Its not a big deal and certainly not worth complaining about, it takes less than 1 minute to flip a fan around and doesnt touch the warranty stickers.
I haven't had the issue with my miners, but one of my clients couldn't simply flip the fan , because the other side of the intake fan was not flat enough to fit the the grill , so i had to send him a spare fan.
i also once had a brand new miner that vibrates like an old nokia mobile, it would even jump of the rack , turns out the intake fan motor was faulty, i could manually spin it and feel the instability of the rotation. so you are 100% right , bitmain will just attach whatever fans at their disposal most likely the cheapest ,as i personally have seen a dozen of different fans from bitmain too.