I 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. The foco theory is really another version of the Narodnik theory, which Lenin had criticized