the walls have moved from vertical as built as a result of the ground around the foundations allowing the foundations to move over hundreds of years but those wall were heavily over engineered and over sized.you can see walls that are out of plumb, yet have stood for hundreds of years.
When we built a house on 22 pad foundations each hole was 2 foot by 2 foot by 4 or 5 foot deep. The Building Control Officer and the architect required that the bottoms of these holes were flat and level. Otherwise there would be a possibility of the base of the concrete moving sideways over time.