Looks like the same family -
6801-00 (Grey Co): David B. SMALL, 36, farmer, Ontario, Michigan USA, s/o John SMALL & Jessie HAY, married Margaret DAY, 23, Michigan USA, same, d/o William DAY & Hannah BURNS, witn: Etta W. SMALL of Michigan USA & Jeannie DUFF of Illinois USA, 29 Aug 1900 at Hanover
4277-90 Alan DUFF, 25, railroad construction, Campbellville, same, s/o Alex DUFF & Christine MCGIBB married Jennie D. SMALL, 22, Hanover, same, d/o John SMALL & Jessie HAY, Wtn: Dr. & Mrs. LANDERKIN both of Hanover November 5, 1890 at Hanover.
Mother's 1st name wrong??
001546/78 (Bruce Co) Sebastian FRYFOGEL, 26, farmer, North Easthope Ontario, Turnberry, s/o John FRYFOGEL & Catherine McFARLANE, married Jessie SMALL, 23, Waterloo Ontario, Hanover Bruce, d/o John SMALL & Catherine HAY, witn: John FRYFOGEL of Turnberry & Ellen BELL of Walkerton, 2 January 1878, Walkerton