pixiv tag with リヒャ父 (Richard's father) and it's said in the commentary that the log is heavily focus on his father.
It's been a long time since I last played this game but iirc Richard hate armor (or at least, prefer leather/light armor). With all the hint about his father (forced him to do swordmanship, Mueller killed him and rescued Richard, Richard's affection to Mueller) ~> Richard's father might have the armory soldier appearance as oppose to easygoing Richard.
Another post of Richard's father by this artist: pixiv #29050273