Zach and the others weren't waiting outside the village. They had moved on from Mick's route and had begun targeting other settlements which paid tribute to the raiders.
Though many of the men used different paths every day to throw off pursuers, especially after the death of Marcus and his crew. They all fundamentally converged on the same point after their daily runs.
And that was the foundry. So… the plan was simple: wait just outside the foundry and tail the raiders with a mixture of aerial reconnaissance and personal stalking.
Each time they cemented a route, they established contact with the settlement most perturbed by the Raiders and their constant exploitation.
There they fulfilled a similar transaction. Intelligence and sabotage in exchange for security and the promise of working towards a similar aim.
