How would that even make any sense anyway (it is not technically feasible). Individual soldiers may have earned their commission to advance up the social rank, but entire units wouldn't. You would never find a general saying to a full formation of poor men that because they had done well in that last battle they could all enjoy more land to provide themselves with better armour. Its very gamey and not historical by any means or understanding. A unit is not the same people appearing in each battle each time, but an abstraction of your faction employing that number of soldiers equipped in that particular way.
Foot
Bookmarks