It looks to me like nine shots for an HDR in this case was more than what was needed. In some cases too many shots can do just the reverse of an HDR. There is loss of detail in both the shadows and highlights. On an overcast, gray day there is little contrast for a nine shot HDR to work with. On a day like that a one stop range over three shots or even a 1/3, or 1/2 stop range might have worked much better. HDR is most effective with a wide contrast range, dark shadows and bright highlights. In HDR "more" is not always better.