Tt is important to keep in mind that this is not a normal function, as isolated rotation is not. not a normal movement pattern. It is true that these muscles do not do the main work during the overhead press, but they are used to stabilize the entire movement, which means that over time and the increased load, they become stronger and do their job better.
For comparison, the bench press does not involve the external rotators too much, especially when comparing the load that the pectoral muscles and the anterior heads of the deltoids must bear at this stage. A situation in which the muscles that rotate the arm outward are much stronger than the muscles slowing down the arm during a throw or impact from the internal rotators can lead to frequent injuries.
In addition, one of the hallmarks of the bench press is the shoulder lift in the last phase of the upward movement of the barbell, thereby engaging the trapezius muscles. As a result, the weight is kept above the head by the hands locked in the elbows, whose direct support is provided by the shoulder blades, and these are stabilized thanks to the involvement of the already mentioned trapezius muscle, whose lifting immobilizes and actively supports the squeezed weight.
Tension in the trapezius muscles pulls the upper edges of the shoulder blades towards the spine, while lifting the shoulders brings them up. This movement directs the joint cavity upwards, the purpose of which is to directly support the humerus from below and move corvoid and shoulder processes away from it. So if we perform the head press correctly while standing, the shoulder blades will certainly position themselves correctly, but we will also avoid the compression of the ligaments of the rotator cuff and the associated pain.