Put the strongest at the front, so that when the guard brings the muzzle of the gun close, they push down on their hands, up on the muzzle, and kick onto the Iconian, successfully grabbing the gun. Be sure to keep the Iconian between you and the other guard for meat shielding purposes.
Also maybe twist the gun a little bit.
If they could also spit on the Iconian's visor to temporarily disorient them, that would be nice. If the others have weapons, fire into the Iconian's face so that he can be all the more disoriented. If needed to cover the situation, the other Iconian does not have a helmet, so you could shoot him in the face.