There's also the fact that the metal-banded bucket in the well was invented after the mechanical water pump. No one in history used a metal-banded bucket because the metal would just rust after the first day of using it. You might make a metal band in order to tighten the planks together, but you'd have to replace it with rope or something. Until galvanization technology was invented, metal in and on buckets wasn't a thing. These people are living in a post-apocalyptic society that is using technology that they have no idea how to reproduce or maintain properly.