Putting aside the "railway clerk" description for Joseph Steacy's father in that 1898 marriage record for a moment, here's another speculative punt to follow up on as a potential father for Joseph. It's a Robert Bartholomew Stacey who like Joseph was also a Colour Sergeant (15th Regiment), and served time in Tipperary to boot, for he had a son Robert Somers Crawford Stacey there on 28 August 1879, the birth took place at the Military Barracks, the mother was Jessy Jane Shaw:
https://www.irishgenealogy.ie/files/civil/birth_returns/births_1879/02906/2064938.pdfI can see a marriage record for this couple, the marriage took place on 26 September 1878 at the Parish Church, Fulwood, Lancashire, Robert was 25 and his father was stated as John Thomas Stacey, a farmer, she was 20 and her father was David Shaw, a civil engineer, the address for both was Fulwood Barracks, where he was a sergeant in the 15th Regt.
I suppose the question is, long before he married Jessy, did any of his prior service bring him to Ireland and more speciically into proximity with Anastasia (Kane) Tubbert? Worth pursuing, if only to eliminate him.