By logical nference:
Genesis 19:12
Then the men said to Lot, "Have you anyone else here? Son-in-law,
your sons, your
daughters, and whomever you have in the city—take [them] out of this place!
The angels mention "sons" plural. more than one.
two choices:
- The angels sent by God to rescue Lot and his family have no idea whatsoever what Lot's family consists of and they are totally winging it the whole time.
- The angels sent by omniscient God to rescue Lot and his family know everything about Lot and exactly who his family consists of.
i believe the second option to be in keeping with what is said elsewhere in scripture of angels sent directly to specific people, therefore i believe Lot has more than one son, and if he has exactly 2 then the number 10 in Genesis 18:32 is perfectly explained.
with those two things in hand, Occam's razor.