Metallinatus
Projectiles can win certain fighting games. It has happened many many times in the past. Ukyo from samurai showdown 2, prime example.
I loved samsh2 and played it quite competitively back in the day, a genjuro main in fact. Ukyo's fireball was stupidly designed.
I really enjoyed the game, despite the fact that it was a balance disaster. It was enormously fun.
Things are different today, it's 2015 and we know a lot more about game design and game balance.
Shiek has un-reactable invisible needles that travel a full stage and confirm into kill moves like bouncing fish, useful in both camping and approach, from the air and the ground.
Samus has a 20 frame startup 5 damage missile that isn't safe on block or hit, does not home, all but pointless in the air, can be cut/punched away AND hit her simultaneously, with a full second of cooldown and all but no follow ups.
From a game design perspective, taking just these 2 projectile moves in abstraction, you would have to be an idiot to design these 2 moves in the same game. It's almost childishly bad design.
Do I love smash 4? Absolutely, it's a great game, even a fantastic game. It's enormously fun, and I really love playing Samus in smash 4.
In adjusting and balancing this game, you should not kid yourself, there's a huge disparity and it's not merely going to come from balancing up the low tiers, the high tiers are going to have to be nerfed because their design is fundamentally flawed.
It won't happen without nerfs.