Complex sentence: However, Marinesko was not awarded with the "Hero of the Soviet Union" title: his commanders refused to trust reports regarding the scale of the hit; in addition, he was deemed a controversial person, "not suitable to be a hero".
Split into simpler sentences: However, Marinesko was not awarded with the "Hero of the Soviet Union" title. His commanders refused to trust reports regarding the scale of the hits; in addition, he was deemed a controversial person, "not suitable to be a hero".