Toe faaigoaina i le vaegaau ia Fepuari 1927, na tofia ai Parkhomenko e avea ma ta'ita'i o le 87th Transbaikal Cavalry Regiment o le 9th Far Eastern Separate Cavalry Brigade i Spassk, na ia ta'ita'ia le regiment i le feteenaiga a Saina-Soviet o le 1929
. Na faauu o ia mai le Novocherkassk Cavalry Officers Improvement Course (KUKS) i le 1929 ma le Higher Academic Course i le Frunze Military Academy i le 1930. Na puʻea faapagota Parkhomenko iā Iulai 1931, ma faateʻa mai le vaegaʻau, ma faia se suʻesuʻega. Na faasalaina o ia i le tolu tausaga i le falepuipui e le Military Collegium o le Faamasinoga Maualuga o le Soviet Union mo le "le usitaia o poloaiga a le Revolutionary Military Council ma le [military] itumalo i le faaputuina ma le faaeteete o auupega", ae na faamagaloina ia Oketopa.