Harper: although he's doing well for himself now, I think he should have gone face and Rowan should have gone heel. Harper's bigger, slower, and generally limited in the ring, all things that lend themselves toward being a heel. Harper on the other hand is much faster and more agile, and has a much more fan-friendly, varied moveset. He's one of the most athletic big men the WWE has had in a very long time (maybe the most athletic since Lesnar in fact.)
They should give him a less generic theme song w/vocals (some country/rock mash-up sort of thing), make him cut his beard ad hair slightly (but not too much, just so he looks less like a cannibal/serial killer), change up his attire slightly (white short-sleeved t-shirt w/a new dark-colored logo on it, black jean/leather sleeveless jacket, still the blue jeans), and sell both as merchandise items. He could/should also give the handkerchief in his pocket (or a bandana as part of the repackage) to some fan in the audience (or throw it into the audience prior to executing his finisher.) I firmly believe Harper could make an awesome badass, blue-collar face if pushed correctly and made into more of a biker and less of a deranged hick.
Wyatt: He really should have been repackaged given how badly Cena buried him. I'd try and revamp him into a darker version of Mick Foley with three personalities (Husky Harris, Bray Wyatt, and Axel Mulligan.) "Bray" would be under the impression that Husky and Axel are two of his henchmen, Axel could be portrayed as a mercenary type only following Wyatt to cause mayhem (but he isn't above trying to usurp him if he thinks that would cause more chaos), Husky could be trying to break free of his influence, etc. Each personality could have varying alignments between heel, tweener, and face, with slightly different wrestling styles, etc.
I'd also give Wyatt his own logo to enable him to generate some sales (I'd make it a stylized open palm below a lantern with the world inside the lantern) and start selling merchandise for him, like the hat. He could sell well too if given the chance.