Interesting question, Dave,
If you listen to talks by Burmese-trained monks in the Mahasi/U Pandita lineage, such as
U Vivekananda posting.php?mode=reply&f=16&t=9879
it is clear that (in their view) they are teaching from experience of the paths, and that stream entry is quite possible for lay people willing to put in sufficient effort.
Similarly for Joseph Goldstein , Steve Armstrong (who spent a couple of years as a monk in Burma), and other lay teachers.
I mention the above in particular only because they are teachers I'm familiar with, so they are the ones for which I've registered that message.