I wonder if it was George?
Medal card of Hillman, George
Corps: Royal Sussex Regiment
Regiment No: L/10956
the medal card for this shows that he was in R Suss R/ R W Kent Reg/ R Suss R which would fit OK with this information maybe?
http://www.1914-1918.net/sussex.htm11th (Service) Battalion (1st South Down)
Formed at Bexhill on 7 September 1914 by Lieut-Col. Lowther, MP and Committee. Moved to Maidstone in July 1915 and then adopted by the War Office. Moved to Aldershot in September 1915.
October 1915 : moved to Witley and attached to 116th Brigade in 39th Division.
Landed at Le Havre in March 1916.
23 May 1918 : reduced to cadre strength.
30 June 1918 : transferred to 75th Brigade in 25th Division. Moved back to England, going to Aldershot.
July 1918 : absorbed the 13th Bn, the
Royal West Kents.9 September 1918: Brigade renamed 236th Brigade and left Division. Sailed from Dundee for North Russia 17 October 1918.
I'm way out of my comfort zone here though
so perhaps someone else could look at it and see if the medal roll numbers would fit?