I made it! didn't realize you could equip the great sword and hammer at the same time.
The story continues. Thank you so much.
Might have to do a second play through making new choices.
I managed to complete it somewhat unconventionally, with only edged damage (bursting down one character even if the 2v1 after is drawn out), Lia's repositioning ability actually ends up splitting the damage almost perfectly evenly with no need for a shield (11/11 stats), altho only won the fight by a sliver with both characters alive still