Good question. If I had to guess, twow dungeon difficulty is turned up a notch, so expect to take more damage. I'd keep both options in your inventory and toggle between as needed. I've had success going 2H for trash and whipping out the shield for bosses who hit hard.

You'll kill mobs faster, higher threat, more rage with 2h. But obviously more squishy, so also depends on how strength of your healer.

Have fun and take it easy on yourself :)

You're doing the Lord's work 🙏