Ladies and gentlemen, i dont think that only the shotguns are the problem.
I think the damage output from all the guns in the game is getting unrealistic.
It is so high that soon we won't feel the difference between wearing armor and not, if it continues like this.
So called tanks are able to survive 2-3 bursts from heavy weapons. "Tank" has lost its meaning because the only difference is if you will die from 1, or 2 bursts. We have pistols that are able to shoot through APA, we are able to create characters that can shoot plasma rifles 15 times, wiping out a small army in one turn. Snipers ale meaningless, because who bothers to cripple an incoming dude, if you can just burst him away from 35 hexes? PvE is becoming jokingly easy with all those weapon buffs. And now, you can just shoot away any dude that comes your way with shotguns, while in reality, they shouldn't be able to penetrate metal armors, not to mention high-tech-space-technology combat armors.
IMO, if you want to throw some balance into game, stop buffing damage of all the guns, it leads nowhere. Either nerf them, or increase effectiveness of armors. Make the combat more tactical by adjusting the crit chances of e.g. sniper rifles, reduce effectiveness of miniguns at long ranges (is that possible to implement?). Because now, it looks like it only matters who has more avengers in their team.