Because only the ones on the field have equipment, rest are naked.

I'm specifically answering this part of the question "Also why does the power change when moving someone from the recruited to the field? I know it will change when placing them on the grid depending on what tactics you are using and placement but I don't think it would (or should) change by 1k+."

I think currently, it is sorted by level and then power in the team interface, and as it's easy to max level all ninjas (I have literally thousands of each of the food stuff), I think everything is fine?