Call Ducks,
I'm no expert here, and no broody here either, but here's my two cents anyway
I would think it would depend on how much time you can spend watching the incubator, and is it trustworthy? Also, are these broody hens "proven" to hatch out a clutch, or are they first timers? Will they be good mothers to the chicks? If they are good, proven broodies, then I'd say let them do it. But if there is any doubt, I would hatch them in the bator. Me, personally, think I would use the incubator anyway. Kind of a control freak with things like that!
Just my opinion, I'm sure others with more experience will chime in. Good luck either way you go!
I'm no expert here, and no broody here either, but here's my two cents anyway

