Flails: Of the flail weapons that exist, most use a small number of flails(2-4) and generally heavier components. I'd think a good compromise point would be flails are fine, in small numbers and when using heavy impact components(hammers, heavy blades, etc...)
I think a good guideline for IRL realistic is if you can find a real life example of what you're trying to do, it should be allowed. If the realism is at all debatable and you can't find a real life example, it's not allowed. Example: Flails do exist in real life. There are several examples of bots with 2 flails on a spinner. But 8 flails? No. Similarly, hinged wedges/forks do exist in real life. But huge long 120cm angled sheets? That's taking it too far.
Maybe the more specific version would be related to long wedges that are essentially parallel to the combat surface.