The vanilla behavior pack file trading\economy_trades\weapon_smith_trades.json is in error at line 94. The error specifies that the V2 weapon smith will trade 2 emeralds for 2 enchanted iron swords, but it should only offer 1.

Note that the error does not actually result in offering 2 swords in the vanilla game, presumably because some part of this trade is hard-coded rather than data-driven. Depending on what the conditions are for the hard coding to be invoked, there might be implications for an add-on behavior pack. For example, it might not be possible for a V2 villager to give 2 enchanted items of any kind in a single trade. It's not clear whether this limitation is intentional, and I'm not aware of it being documented anywhere.