The more I look at it, the more I think these are billhooks.
Here's the puzzle: most billhooks are single-handed tools (amply illustrated by
http://billhooks.co.uk/). The weird thing is that most weaponized billhooks are presented as two-handed and long-handled, mostly based on a few late models in museums.
Kind of weird, no? I'd suggest that these mysterious weapons are weaponized one-hand bills, which are by far the most common type of bill. They've also been present in Europe since Pre-Roman times.
I'd also suggest checking out the diversity of shapes subsumed under the general term "billhook" (see
http://billhooks.co.uk/photos-and-other-images/ and the pages following it). I think, if you prowl through, you'll find some familiar looking shapes.
My 0.0002 conjectural cents,
F