Make a pass through Policy.Helpers and consider making the code less dry and easier to understand

From our conversation in #919, I believe the `Policy.Helpers` module is due for another pass and possibly a rewrite.

When I initially wrote it, I did so with a strong emphasis on making it as dry as possible, probably at the cost of clarity. Some namings were also unfortunate.

I'm not really sure what needs to happen, but it's due to a review, at the very least.