Goblins without resources

It seems to me there needs to be a way to bypass a goblin town (in the PvE part of the game) once the town has no resources, even if victory was not attained.

I understand that the game is not aimed at PvE, but as long as it's part of the game, this could use to be looked into.

Why would there be a way to bypass the town?

You get to the next town by beating the one before it, just because you robbed them of all their loot doesn't mean they will let you pass.