I'd be very interested if you found the Missing Men files for Officers. Presumably they would not be at TNA or they would be available - or is that too naïve?
World War 2 Royal Warwickshire 2nd Lieutenant's grave identified after almost 77 years (11 April 2017) World War 2 Royal Warwickshire 2nd Lieutenant's grave identified after almost 77 years - GOV.UK TD
Just in case it helps anyone: British Army Casualty List No. 228 Dated 11 June 1940 Missing The Royal Warwickshire Regt 45247 Sparrow Capt AH – 8 Bn – 21.5.40 45167 Spencer Capt HN – 7 Bn – Date Not Reported 105017 Strawson 2nd Lt LP – 8 Bn – 21.5.40 113341 Thomas 2nd Lt HLJ – 8 Bn – 21.5.40 88597 Varley 2nd Lt Jp – 1/7 Bn – DNR 113344 Wensley 2nd Lt AJ – DNR Casualty List No. 1091 Dated 24 March 1943 Previously reported missing now presumed KIA 8th Bn Royal Warwickshire Regt 105017 Strawson 2nd Lt LP – 21.5.40 British Army List of Missing March 1941 Officers Missing The Royal Warwickshire Regt 53157 Capt Allen, James Frazer Lynn 88155 2nd Lieut Batten, Gerald Mortimer 52949 Lieut Dunwell, Charles Leonard 91182 2nd Lieut Hewitt, Seymour Lovell 102709 2nd Lieut Hope-Jones, Kenneth 107109 2nd Lieut King, William Arthur 15472 Major Rance, James Edward Weeks 45247 Captain Sparrow, Alfred Harry 105017 2nd Lieut Strawson, Lawrence Paul 113341 2nd Lieut Thomas, Harold Leonard James 113344 2nd Lieut Wensley, Arthur John British Army List of Missing April 1942 Officers Missing The Royal Warwickshire Regt 53157 Capt Allen, James Frazer Lynn 105017 2nd Lieut Strawson, Lawrence Paul 113341 2nd Lieut Thomas, Harold Leonard James