Afterwards, Robertson went on to attend a series of shorter training courses in Britain. He attended the School of Musketry at Hythe, Kent; the Machine Gun School at Netheravon, Wiltshire; the Artillery College at Woolwich; the Anti-Gas School at Porton Down; the Anti-Aircraft School at Westerham, Kent; and the Royal Tank Corps School at Woolwich. He returned to Australia in 1925 to become Chief Instructor at the Small Arms School at Randwick, New South Wales in 1926. Following the retirement of General Sir Harry Chauvel in 1930, Robertson was posted to the 7th Infantry Brigade as its brigade major. In 1931 he became brigade major of the 1st Cavalry Brigade in Queensland. He returned to Sydney in February 1934 as General Staff Officer (Grade 2) at the 2nd District Base. In June 1934, he was appointed Director of Military Art at the Royal Military College, which had been transferred to Victoria Barracks, Sydney, as a cost-cutting measure during the Great Depression. It returned to Canberra in 1937, and Robertson returned with it.