jonesy
A Wicked Kendragon
That's a good point. It's harder to make wandering monsters work.Wandering NPCs usually turn into some good RPing, while wandering monsters just on a battle grid don't seem to be as fun as NPCs.
You can place wandering NPCs onto a scene practically without any behind the scenes information and players will then assign to them atrributes that just weren't there to begin with. The encounter then grows out of the players imagination, or the DM's response to their response.
With pure monsters that's harder to do as they seem to require more initial setup and backstory, and then they are no longer just wandering monsters.