@Jeirien See, the thing is, this world established that there's a given hero per demon lord regardless. That hero is fated to kill them even if he doesn't go after them first, so there's no reason to not go for the easiest opportunity, because indeed, just giving a hero an opportunity to become really strong is the worst possible move, even if going after them at the start is tropey.
It's not like the Maou wants to wipe out a village anyways, he wants to wipe out a specific hero-to-be.
Anyways, we'll see how this goes, I could see it having some bad execution like you expect, or see it being done decently, since the whole premise is him being a 'realist', someone who'd actually do a proper job of it.