If you avoid initiating the conversation with him, the two human/drow/humanoids will patrol a bit and conveniently both stop under a large chandelier that has a little pin holding it up. Dropping it can one-shot them both.
There are candles all over that dais that will ignite grease pools.
There’s a wooden bridge behind and above Dror that will easily break and drop whoever is standing on it into the chasm.
Knock a goblin into the pit behind them and there are two spiders that will eat them.
Using the environment to your advantage helps a ton.