I'm not sure I understand the connection you're drawing with human rights.
Officers and men live separately -- have separate dining halls, quarters, clubs, &c -- to some degree even when they're not in camps. This is generally seen to contribute to the ability of officers to maintain order among the enlisted. The separation helps officers to remain coordinated with each other as well as allowing things to be somewhat less personal between officers and enlisted. It may not sound nice to us, outside the military; but it's not something the people writing the convention came up with and it's not something they had it in their power to do anything about. They were trying to bring some order to the treatment of prisoners of war, not reorganize the militaries of the world on egalitarian lines.
So it's not so much about people on the side of the detaining power who "...can only think in hierarchies..." as it is about the social system that prisoners are a part of immediately before they are captured, and respect for that social system, as offering both continuity and a semblance of order for prisoners. A commentary maintained by the ICRC puts it this way:
...leaving the hierarchy of the battlefield intact in prisoner-of-war camps serves the interests of both the Detaining Power and the Power on which the prisoners depend. Retaining a functioning command structure among prisoners of war of one Party will usually have a positive effect on camp order and discipline, which can be an important factor in ensuring the best possible conditions of internment for all prisoners of war. Differential treatment involving privileges for higher-ranking prisoners is one way of maintaining this structure.
Officers and men live separately -- have separate dining halls, quarters, clubs, &c -- to some degree even when they're not in camps. This is generally seen to contribute to the ability of officers to maintain order among the enlisted. The separation helps officers to remain coordinated with each other as well as allowing things to be somewhat less personal between officers and enlisted. It may not sound nice to us, outside the military; but it's not something the people writing the convention came up with and it's not something they had it in their power to do anything about. They were trying to bring some order to the treatment of prisoners of war, not reorganize the militaries of the world on egalitarian lines.
So it's not so much about people on the side of the detaining power who "...can only think in hierarchies..." as it is about the social system that prisoners are a part of immediately before they are captured, and respect for that social system, as offering both continuity and a semblance of order for prisoners. A commentary maintained by the ICRC puts it this way:
https://ihl-databases.icrc.org/en/ihl-treaties/gciii-1949/ar...
...leaving the hierarchy of the battlefield intact in prisoner-of-war camps serves the interests of both the Detaining Power and the Power on which the prisoners depend. Retaining a functioning command structure among prisoners of war of one Party will usually have a positive effect on camp order and discipline, which can be an important factor in ensuring the best possible conditions of internment for all prisoners of war. Differential treatment involving privileges for higher-ranking prisoners is one way of maintaining this structure.