You may be working the wrong angles, yet again.

If they could not yet read or write, I would only wonder just how important it would have been, considering how *little* we seem to prove to know about their required lifestyle. Sometimes things are not as they appear, JoeB. His daughters, even if, as you seem to suggest, were dumb as twits, they had every capability to become highly successful wives to men of that day and if nothing else proves such, their subjected thoughts and actions thereafter with their father proves it. Not many women could live under those conditions and still be able to yhink strategically... Then, yet, perhaps there are more than even I know.
Or perhaps you are doing theological and philosophical handstands to let Lot and Yahweh off the hook for their bad behavior.
Please tell me what world you live in where a man could get BOTH of his teenage daughters pregnant, and get away with the excuse "Well, they got me drunk. Twice!"
NOw, if you look at the story with a cynical eye, it makes sense.
The Hebrews were fighting a long term genocidal war with the Moabites and Ammonites over this crappy little strip of land they are still fighting over today.
"Gee, they desecnded from Lot, which means they have as good a claim as we do. how do we bolster our case that it's our land?"
"I know, let's write something into the bible about how they were the result of an incestuous union between Lot and his daughters!"
In short, it was a story that was made up as propaganda.
I think the actual best person is this story is Mrs. Lot, and she got turned into a pillar of salt.