A while ago we planned to buff Diana's jungle (passive deal 110% damage to jungle monsters, it was going to be 125%) but it turns out she was already just fine as a jungler. We left it at 110% to help signal she is fine as a jungler and give her that little extra boost, but the truth is she doesn't need it, she is already fine.
Fizz and Morgana are similar in that they are also fine junglers that many players overlook.