And this is why keeping the Druid wildshape as currently designed in 5e is probably the best solution. Too many players playing the class too many different ways (all valid) for any kind of template structure to work. I wrote this for how I've seen a Druid played, but that doesn't begin to cover the wealth of options for the class. Perhaps the only thing really needed is
@Clint_L 's suggestion regarding lowering the CR of Moon Druids in early levels (if people are truly concerned about Druid being OP at that point).