I believe that a significant part of the circumstantial linkage is in the distinct names in the families of this proposed Wilson family. Dixon, as Debbie pointed out, but also Annabella. The proximity of some of the Mulmur and Nottawasaga farms in combination to this adds to the argument I think.
Charles Stewart (Mary Wilson), Dixon Wilson, George Wilson, John Wilson, William Millie (Annabella Wilson), and Joseph Wilson all had farms in north Mulmur / south Nottawasaga south of Creemore. Joseph resided with Annabella before marrying a neighbouring widow. Dixon and Annabella married siblings. Dixon's farm was on the next concession east of George and John's adjacent farms. Mary (Stewart) was very near to those farms.
My great great grandfather was John Quinn. He married Annabella Stewart, daughter of Mary Wilson and I believe namesake of her aunt Annabella (Millie). Their children have several links to the proposed Wilson clan. John and Annabella Quinn's children included: Mary, John James, Mary Ann, George, Norman Dixon, and Wilson Stewart Quinn. Annabella's brothers and sisters included George, Ellen Mary, Dixon and Johnson Stewart.
Dwight, your Alexander Wilson also had a son named Dixon. So did George Wilson. These families account for (almost if not) all of the instances of Dixon as a first name in the 61 and 71 Census records for the area.