One-handed flails may or may not have actually been weapons.
Yeah ok, whatever, in the context of reenactment or HEMA that matters. But this is D AND FUCKING D, so whatever.
I fucking hate flails. Not because they aren't sick as fuck (THEY ARE). Not because they probably weren't real (Dragons anyone?). Because you always get some nerd that wants special powers for their flail, and since like a dumbass you didn't scrub it from the available equipment list you now have to make up some fucking rules for flails.
Treat them like axes, only shitty because they can't chop wood. That means axes and flails should both be able to do shit like tripping, hooking, disarming and shit like that.
PS let Flail Snails do that shit.