In my play, I have found that scouts are extremely useful, not just for scouting, but to station them so they keep an eye on my borders. Getting a couple of extra turns of warning time to try to get troops (if avaiable) to help defend against a rampaging spider army is golden. But, a possibile game mechanic occurs to me:
In addition to the warning for hostile creatures in my ZOC, I think that there should be a separate warning for seeing moving hostiles that are outside my ZOC but inside my sight radius. Otherwise, I have to manually look over my map every turn to see if any monster spawns have popped up.
Why use scouts for this and not outposts? Well, scouts are mobile. If a monster pops up, I can move the scout out of the way. Can't do that with outposts. Plus, the scout's sight radius is much, much better for a similar amount of resources spent.