I think you have hit the nail on the head. Attached map and LIDAR gives a better idea of how the land rises from the valley floor up to Little Rollright. Had a trip on Google street view from the valley up to the village but the roads are bounded with ridiculously high hedges as are all the fields.View attachment 812381
Re the above.
It has been noted that the aircraft was probably descending as part of its planned bombing run however the 22 degrees may equally come from flying straight and level into a 22 degree rising slope.
I would suspect that the impact angle is actually a combination of decent angle and rising ground.