Shanks lose his arm, but don’t lose his power according to oda. Kidd lose his arm , yet no one arguing Kidd is nerfed or losing his power. in timeskip . perospero lose his arm but still able to fight and don’t lose his power.
King without one wing is not nerf or losing his power #StopKingDisrespect.
One wing king still low diff katakuri and can beat Marco in fight by 50 % chance.