I have several two-handed top swords from the Thrall War mod, insanely expensive, with 88 damage. I tried them on the purge, and they had less effect than Momentum. Simply because a thrall with a two-handed sword often hesitates. This was permissible in the old purge, but not in the new one, where reaction is everything.
And the vanilla legendary ones are even worse.
Maybe it’s worth trying other maces…