I think I found a way to get rid of the piled halberds in Rattay, I’ve tested it on PC but it should also work on consoles. Disclaimer: it’s tedious.
1.Grab a halberd and jump on your horse.
2.Ride to the alchemy bench and use it (just activate it), the equipped halberd will go to the inventory.
3.Rinse and repeat until you’ve cleaned the streets of Rattay.
4.Go to the alchemist hut west of Neuhoff and dump all your halberds in front of the alchemy station.
5.Sleep save in the bed nearby, the halberds will disappear.
I don’t know if the 2 last steps can be done anywhere, the initial idea was to dump the halberds far enough from Rattay but near an alchemy bench just in case, you might not need to do that, you can test this, just be sure to save before dumping 100 halberds on the ground!