Board Thread:Lore Discussion/@comment-25531876-20141229215535/@comment-4544033-20150213174243

They could pose a threat, if they where able to hit the right spots. You see several times that they have dug into a home or otherwise secure area, and killed everybody. Many of the old Dwemer ruins can hold them back, but the Falmer seems to have numbers on their side, and numbers can replace skill sometimes.

If they where to dig into a city somehow, either by luck or intention, the town would be unable to rally in time to do much. Even if they did regroup, the cost would be high.