I have been studying Google Earth overviews and contemporary/recent pictures to try to understand why the Russians took the routes that they did. It becomes very obvious when photographs looking up the ravines are studied, as parts of the ravine walls are sheer cliffs, which in turn would be totally impassable to formed troops and in many cases to any troops.
I have transposed these areas on to my map and denoted areas classed as totally impassible as red lines. It then becomes clear why the battle unfolded the way it did - from a terrain perspective. It also explains the British dispositions along the heights.