Has the information been taken from his death certificate? Not always a reliable source.
Have you searched on Scotlandspeople for his parents' marriage and his baptism/birth.
http://www.scotlandspeople.gov.uk/Do you have his 1888 marriage certificate? If so what was his father's occupation?
Info contributed to find-a-grave
William came from Stirlingshire Scotland sometime around 1888 where he came to Hamilton Victoria where he met his wife Isabella Henderson.Have you considered he may have arrived in South Australia before travelling to Hamilton, Vic?
You may have to accept that there is no surviving record of Wm's arrival. Not all shipping manifests survive. I have a copy of an ancestor's diary which includes details of the journey to and arrival in Melbourne, Vic and the name of the ship. The family's name does not appear on the ship's manifest at PROV.
Have your searched all the
FLEMING arrivals 1887-1888 at PROV? Some entries are simply Mr
FLEMING and not all ages are accurate.
Cando