I am not sure how or if the actual "size" (meaning pounds) plays a difference. I could be the exception but Elton is really small with no SM at an older age. However, I've been told that Ella had more of the domed skull but she was larger (especially on prednisone) in "size" but not sure in relation to her head vs. Elton's.
I wanted to edit this and delete it but just read post on a FB group and maybe size is something in the future. I just know Elton is one of the smallest cavaliers ive seen.