how would heavy even fight in smash bros
like his normal attacks would have to all be punches, because he doesn't really have anything else going for him beyond his forgetin minigun
maybe all of his smash attacks could cause teammates to show up and drop in quick attacks
like up-b causes the soldier to drop in, fire a rocket at heavy's feet, then disappear off the side or bottom of the screen (or just jump up off the top if he can't actually escape); the rocket is always fired at the same angle and does pretty decent damage, but isn't actually spawned FROM the player, making it as unorthodox as Ness' PK thunder
side-b could just be a quick projectile from the sniper, and holding B allows the sniper to stay where you summoned him to charge up a stronger attack
down-b could be a trap attack, allowing heavy to 'place' a spy who will then attack when you press down-b again, but only the specific place you dropped him, to cause anyone hit to fly in explicitly the direction you were pointing before the attack fired
though i don't know about the normal-b. maybe it could be a mundane-ass shotgun attack that always fires straight forward, but doesn't actually do knockback- it just allows heavy to catch opponents and then proceed to combo them