Here is a funny collision between mods that I just witnessed.
I was checking out the Fallenleaf grove (part of Unique Landscapes), next to Silorn (south of Skingrad).
The grove ends with a very sharp cliff right up to the Shrine of Akatosh. At the bottom of the cliff is a pond where I found a few Pilgrims of Akatosh quite disorinted. Some were even dead, floating in the pond. The survivors were looking up the cliff, wondering how they could get back up.
I believe they spawned at the shrine, started walking and fell to their death.
See the screenshot