I was going by that also, Treetotal.
Have now checked GRONI's database for marriages 1918-1924, in addition to the earlier 1936-1943 search and these are only results between a Hamilton and Robb/Noble/Martin-
William Hamilton m.(5 June 1919 Strabane district) ? Robb
Minnie Hamilton m.(1 June 1922 Fermanagh district) Matthew Robb
Agnes Hamilton m.(10 July 1924 Belfast) William Martin