@Riot are there any champs that need to be balanced a little high?

I know, I know, winrate isn't everything. However in the past, riot has talked about how some champs need an average win rate to be a little bit lower to keep them from getting out of hand. People like leblanc, or akali, or lee sin... basically champs that can crap on the other team too easily when good. What I'm wondering about is the other end of the spectrum. Are there any champs in LOL who need a win rate that's a little higher than average in order to be in the right spot.

Now someone might wonder why a champ might need to be better than average to be in the right spot. Well there are power curves in a lot games. In those games there are definitely cards above and below the curve. Now the ones that are bad exist on purpose and they exist for a good reason. Note I'm sure many of the things Rosewater talked about in his columns apply to LOL's champs at some level.

Now with those things in mind, logically some champions need to either be better than average because Live Balance isn't perfect, there needs to be a renekton bar, and I would assume that if some champs were balanced towards 50% winrates, they might either fall off the earth or won't be good enough to do their jobs when they need to. So I'm curious which champions riot feels need to be a little over 50% and why the devs think so.

My personal opinion: Amumu and Rammus: these two aren't very commonly seen in games despite their crazy high winrates. Part of me wants to say that riot keeps them good because if these two were nerfed, they wouldn't see play at all (no one plays jungle tanks that much), and they might not be able to do their jobs. I'm also thinking that if they were nerfed, that might force riot to do a big rework on both of them sooner rather than later and the champ up team isn't ready to deal with these two. I also think their rarity helps their win rate some.

Janna - the once and future queen of win rate seems like another one of those champs you have to keep a little high. She's very good at what she does and is very focused. People know when to pick her and she's good at both protecting the carry and dealing with the ever popular leona (and divers in general). However, she's mostly utility and no stats (reverse irelia?) and if she loses too much utility which is the biggest thing about her you can nerf, she's nothing. So Janna has to be kind of high on the power curve because she's a one trick pony with a narrow focus.

Sona - Meddler recently said that despite being able to win a lot at low to mid elos, she's also very unsatisfying as is in terms of her power levels and at higher elos she falls off once the other guys know how to deal with her on the team. I mean she's at 53% win rate and people are still asking for buffs for her. I might be wrong but this means to me that if she were balanced closer to 50%, she might be forgotten about and/or riot would be forced to do another rework on her because the #LCSbigplays rework didn't make her satisfying enough to play.

Ahri - if there's one fanbase riot doesn't want to feel the rage of...

On the serious side, when riot let her win rate fall into 48% or so range a few season ago, the fan favorite kind of got neglected in terms of play rate. I'm thinking that because she's not quite an assassin or a mage she needs to be a little bit on the good side as her kit is kind of in between the two playstyles. I also think that defensive ulting probably is something that keeps her winrate up as she's got a triple flash to try and escape if she needs to. That alone probably bumps her global winrate up a point or two meaning if she were balanced towards 50%, her win rate would really be 48% or so. So while the get out of feeding card is nice if you play it, if you ignore that aspect of her, you might make the rest of her kit too weak to do it's job.

So does anyone agree or disagree? Have anything to add or subtract?