For what its worth. From 'The Waterford War Dead' to be published late this year.
LANDERS, THOMAS. Rank: Private. Regiment or Service: Royal Irish Regiment.
Unit; 2nd Battalion. Date of Death:27-September-1918. Service No:16255. Formerly he was with the Royal Dublin Fusiliers where his number was 30656. Born in Stradbally, Waterford. Enlisted in Dublin while living in Dungarvan, County Waterford. Killed in Action. Grave or Memorial Reference:I. B 19. Cemetery: Moeuvres Communal Cemetery Extension, Nord in France.
Perhaps you might find his records on ancestry.