Read a book on Che Guevara by Jon Lee Anderson. I had many decades back read Che's ' Guerilla Warfare '.
In my opinion Che Guevara was no doubt a brave and honest man, but he was an impatient adventurist, a petty bourgeois revolutionary. Just because the revolution in Cuba took only 2 years or so to be successful, Che thought the same strategy could succeed everywhere, forgetting that the objective conditions were different in other countries.
His foco theory of revolution ( see online ) was a product of his impatience and immaturity, and led to the fiasco in Bolivia.in which he was killed.