transtemporal
Explorer
Scouts do not help at all against roving bandits and marauders that emerge from the wilds, attack in the middle of the night and then disappear back into the wild. Maybe if a town had clear cut all plant matter for miles around it, you can have a watch tower that can give a few minutes warning. But scouts? No. You wouldn't know where to have your scouts patrol, you can't very well send half your town out as scouts to try to patrol every single acre of land for a dozen miles to come. Even if you did, the scouts aren't going to be much faster than the marauders at running back to town so they won't be able to give much warning at all.
Wow, I was just thinking run-of-the-mill banditos. I guess the raiders in your world are like seal team six huh?