Subconsciously, you probably have me spot on. But consciously I merely linked to that particular photo because that is the only one of a fan that I have in a pre-SE/30 Mac.
I now feel like an idiot for having overlooked that. You're right. No additional fan should be required for a Classic.
But if the fan is as noisy as the stock Elina in the SE/30, then it's probably worth swapping out. My SE/30 experience changed dramatically when I installed a quieter Silenx fan in it.