On 21 May 1941 Wimberley was promoted to the acting rank of major-general and became GOC of the 46th Infantry Division, succeeding Major-General Charles Hudson, who had been one of Wimberley's fellow students at the Staff College, Camberley in the late 1920s. The division was a second-line Territorial Army (TA) formation that had fought with the BEF the year before and, like the 5th Division, had suffered heavy losses but was now reformed. He was to remain with the division for just three weeks as, in mid-June, after handing over the 46th to Major-General Miles Dempsey, he returned to the 51st (Highland) Division, this time as its GOC. He was made GOC at the specific request of his predecessor, Ritchie, who was then being posted to the Middle East.