Mao would have claimed to have embraced and extended the Marxist philosophy. But Mao was a complete idiot in every way except as a politician who could play people. Certainly his philosophy was no better than junior-high-school grade.
He was well read and educated, you may disagree with his philosophy, but to say it was 'junior-high-school' grade would be incorrect. From wiki:
'Mao was a prolific writer of political and philosophical literature' 'In China, Mao was considered a master calligrapher during his lifetime' 'Politics aside, Mao is considered one of modern China's most influential literary figures'