i think its intended to be like this unless it really is a bug and noonever ever cared to report it.
i started at the same area (every area where you start gives you a diffrent keep/build layout) and mine look exactly like it. i guess they didnt put (first pic) a wall there since there is no need since its covered by high rocks and a river is in between
the other where there seemed to be random section could be used for some sort of guards in case you get attacked.
but yea looks exactly like mine im pretty sure its inteded to be like it