I haven't read Galula so I can't say whether his writings are exclusively an answer to Maoist revolutionary doctrine. However, history has lots of examples of unconventional warfare that had nothing to do with Mao. Three instances of UW in which the unconventional forces operated in support of larger conventional efforts were the Confederate John S. Mosby's battalion in Virginia during the American Civil War, the SAS and OSS Jedburgh operations in 1944 in France in support of the Normandy landings, and U.S. Army Special Forces as they were originally conceived when founded in the 1950s, stay-behinds in Germany who would promote insurgencies behind Soviet lines in the event WW III broke out. In the 1980s SF adopted the crossed arrows insignia of the old Indian Scouts, poachers turned gamekeepers who if I'm not mistaken were founded by the Army officer George Crook in the 19th century.