Are you in a wetter area? I mentally associate them with river valleys so naively I wouldn't think they'd be drought tolerant at all.

I'm in the bay area of California, so while we do get rain, it's highly seasonal. My pawpaws do need watering in the summer, but it isn't as bad as you might think. They have a pretty deep taproot once established, so a slow drip system just to keep the soil column from drying out can be all you need, which is pretty water-efficient. I'd say they use about as much water as an equivalent-sized stonefruit tree, like a peach or plum, maybe even a little less.