Potentially something big, after finding out how well soft hit of fair confirms I went to lab and I think I found not only a kill set-up but an entire string of mindgames and neutral that could change the entire metagame for the character.
Approach with full hop gunmen > Fall with fair
This is the standard approach. The fair from a full hop has very little range and is only the early hitbox, but with the gunmen at your back it is essentially safe from being grabbed. (unless it's the long shooter)
This fair hitbox confirms into either another fair, or if you have the space a jump canceled sliding usmash. You generally won't slide far enough at kill percent without it. On floatier characters you can try for frisbee or even nair/upair if their di is off.
Next comes the big part, since they know the gunmen is there they will likely hold shield. Now, you COULD grab at this point. Which you may want to at low combo percents.
However, when it's time to kill is when the mix-ups come into play.
If they keep holding shield, start landing with nair or fair depending on the spacing. If nair would hit then always do that.
Except for the quick shooter, even with nair's endlag your endlag is ALWAYS covered by the gunmen. And nair can either kill raw or this soft hit of fair can set up for one.
But, if they were STILL shielding, fsmash. Yes, you heard me. At this point, with the hit from any of the gunmen all the hits of fsmash will connect on their shield at this spacing. This is why i said space the fair, it doesn't have enough push if they're too close but nair doesn't have enough range to always do it.
Fsmash will do one of three things at this point:
1: Poke due to how small their shield is
2: Break their shield
3: Be comboed into by the gunmen or just hit them raw when they try to drop shield/roll out of panic for how small their shield is.
Note: Yes, you CAN be grabbed before the fsmash and after the fair. But if the gunmen break the grab, it can confirm into a kill for you as well. Just watch out for damage kill throws like mario's bthrow, it could hit the gunmen before it saves you.
There may also be mix-ups with frisbee and can since they can be buffered from frame 1. Unsure, but frisbee would be to beat grabs for sure. Spacing it is really hard vs some chars though
That's probably why gunmen shoot the frisbee, it'd be broken if we could double empty land with it lol Though you kinda can with certain gunmen... hmm