The backlash would not be major because so few players play Mii's, though that's partially because of the current limitations. I would have some interest in Mii Gunner if it weren't for the limitations placed on the character. Tiny Mii Gunner became considerably more fun after 1.10 came out. Not to mention many people who are anti-customs are against Mii's being allowed to have anything besides 1111.
Exploding Balloons was affected by the nerf? Are you sure? I heard that move was completely unaffected from the patch.
Samus comes closest to Mii Gunner's play style, but unlike Mii Gunner, she sucks in this game. She is absolutely not worth playing outside of character loyalty. Infuriates me she is so bad in both Brawl and Smash 4 when she was so good in the E3 demo for Smash 4.
I went and tested it before I even posted, just to make sure I wasn't insane. Feel free to double check.
Design wise Swordfighter is Link with a hint of Marth or Ike here and there well at least as normals go specials are all over the place
Jab Links
F-tilt original (i could argue its like his f-smash which is inspired by marth)
up tilt Links
Down tilt Marth
F-smash Marth (it's more of an inspiration rather than a straight 1:1)
Up smash Links
Down Smash Every Swordfighter not named Robin or Shulk
N-air Ike
F-air Links (it's a stretch i know)
B-air Ike
Up air Links
Down Air Kirby?!
His Fsmash is a bit more like Roy's now, though obviously it's Roy that came later. The lack of sweetspot makes the comparison perhaps more accurate of Lucina, or even Smash 64 Link, than Marth.
Dair is a bit like all drill moves, though since his has the downward spike-like behavior Kirby's is probably the most similar.
As for specials, two of them are so blatantly inspired by the Tales series that it's a bit of a wonder they didn't throw Cress/Lloyd/someone in there at launch.
Honestly, at this point I could
almost stand having 1111-2222-3333 options on Miis.
Gunner can go all over the place but 1111 isn't really bad (especially since the grenade nerf). I think generally all that
nobody wants to run is Laser Blaze and Arm Rocket. Stealth Burst isn't exactly useful either.
Brawler can do fine with 2222 and some players prefer that, 2122 being marginally better in a handful of circumstances. 1111 leaves you with a terrible recovery and perhaps the worst down-B in the game, as well as the lack of setups resulting from not having Helicopter Kick or Piston Punch.
Swordfighter is in a rougher spot, though. 1111 sticks you with terrible recovery and a side-B even worse than Jolt Haymaker for self-destructing, and Counter is always situational at best. 2222 sticks you with Shuriken of Light (basically trash), Slash Launcher (not
bad but certainly not
good when compared to just playing Ike), Skyward Slash Dash (pretty bad), but at least you get Reversal Slash to handle obvious projectiles or high and unsafe recoveries. 3333 is probably the best of those, with Power Thrust being passable (if not preferred over counter or reversal slash) and Sword-Rain-I-Mean-Blade-Furry working similar to Shield Breaker in some ways.