[3] Samaniego served during the Chaco War and was later director of Paraguay's Francisco López Military College.

[4][3] After an unsuccessful putsch against President Alfredo Stroessner by Epifanio Méndez Fleitas in 1955, Samaniego was temporarily placed in command of the army's rebellious cavalry division as a stabilizing measure.

[6] Samaniego was noted for his fascination with the religions of Paraguay's indigenous people, published several scholarly articles on the Guaraní people, and is credited with convincing the government to award 13,000 hectares of land to protect the Pai Tavytera, the first instance of official support for native land rights in Paraguay.

[7][8] However, he was also criticized for endorsing Vicente Pistilli's book Vikings in Paraguay, which made a controversial historical case for early Nordic settlement in the country and which some have alleged guided the government's discriminatory policies against the Aché.

[12] Samaniego's son graduated from the United States Military Academy at West Point and was later head of the National Anti-Drug Secretariat during the presidency of Andrés Rodríguez.