Hi Sue
Some observations, perhaps you have already concluded the same...
That would certainly be an unusual name for a French Canadian. But it wouldn't be unusual for a French Canadian to anglicize their name after emmigrating. Of course, it is possible his father was Anglo and his mother French Canadian.
The birthdate you provided above is a good clue, but unfortunately it's not helping me find his CEF attestation, birth, or any census record. (Of course, young teens often fudged their age in order to enlist.) I don't suppose you have any documents pertaining to his army service, like a regimental number?
Do you have any more info on the 1880 finding? It wouldn't have been a census of course. It would also mean Winnifried was much older than Arthur - not impossibly so, but gives me pause.
Have you done an Ancestry DNA test? Genealogy and DNA testing is pretty popular in Canada, you may get some useful matches.
You may also want to update your post with tags such as 'Quebec', 'Canada', 'Great_War' etc. to get more visibility with Wikitreers more clever and knowledgeable than I. Best of luck!