I haven't mentioned them being needed specifically for combat. I'm talking about if their equipment slot is changed it can have a knock-on effect.
If you re-read my above post I clarify all this. You're making this suggestion to have the ability to wear the wings while you wear sunnies.
Since you're mentioning the ammo slot, I'm merely suggesting why/how making that change can have a knock-on effect to others as CURRENTLY sunnies OR wings can be worn while not sacrificing the ammo slot or any other combat related equipment slot - meaning some players might be wearing them because they look cool while they're doing combat.
Players do choose to wear cosmetics in all aspects of the game, so do you see why changing equipment slots can cause a hinderance.
In my opinion, the sunnies should be in the helmet slot and the wings should be in the cape slot to begin with. The reason they're in the Aura slot is so that can worn in all aspects of gameplay.