Man the manga is doing a really big disservice to the novel here. The scale of the battle between the two is incomparable. Here it's like 2 beasts, they go like oh look demon beasts wow now they're dead. Oh slightly bigger beast, oh look it's dead to.
The old man couldnt fight back and they could just stay out of the fire wizard's range. Why didn't the archer chick just shoot them with arrows. Or like stone them to death or something. Not like they were in a position to fight back. There were so many choices they could do I really don't get it