I had this several times in RTR when I migrated Armenia to Iberia. Most of my troops sailed there, but one lone general, which I left to tend Artaxarta(my capital at the start), I migrated by land. He walked through Asia Minor, Greece, Balkans and Cisalpine Gaul, aiding Thracians and Illyrians on the way. He was asked assisatance several times and all the armies left him alone, even though it was 1.2. Uncanny.