Why have a dozen different outfit choices if they are all bland enough and samey enough that it just doesn't really matter what you're wearing? Strong bonuses that influence different aspects of the game make the outfits exciting and unique. Sure...some will feel forced to have to swap outfits before they do anything because they can't bear to do something at less than the maximum possible ability and then they will complain about the constant outfit swapping. That can be mitigated by making the outfit swapping process fast and easy. I would rather see an abstracted instant change than see all the outfits be just differently skinned versions of the same basic advantages just so some people won't feel compelled to swap clothes.
I was thinking more like having sets do interesting things. Just swapping constantly to get optimal gains is not really interesting or fun...
Something like one of the sets giving a modifier to parkour, if you invested in it. Like maybe it allows you to do damage when you land on a zombie, or some kinda aoe.
Or like a fireman outfit that improves the viability of axes, like extending axe range, or making the power attack a much larger aoe. Or maybe he puts fires out and cancels burning on zombies, when hit with an axe, but does massive damage when it happens, so that you would always want to carry a flaming steel axe. Or maybe some unique build using the stone axe.
A Jesus outfit where when you drink normal water in combat, it turns to wine and you get the booze effect. Cheap constant beer for punching.
A set where your hands empty hands become viable weapons, digging, mining and harvesting tools, but you can not use any tools or weapons while the set is equipped.
Maybe a set where when you have the parkour perk, you become able to instantly walk over objects 2 blocks high, without jumping.
A set where you can blind enemies, which allows you to do sneak damage without sneaking, with certain weapons, like bow and knife, but the chance is based on your from the shadows perk level.
A set where you can zipline ;-P
A set where zombie dogs no longer attack you, and are friendly, but it has to be equipped before they aggro you and you have to keep it on.
Anyway, you get the idea. None of that will probably make it into the game, but something more along those lines, rather than 50% more harvest, so that everyone is just constantly swapping outfits...