Cuba has two things that are missing here: more medical expertise and the police enforcing the laws.
Did you notice that the countries most successful at controlling the pandemic are countries where the executive branch is not dependant on parliamentary bickering: China, Germany, Denmark, Vietnam, Switzerland, Cuba, just to mention a few.
But the the worst of all russia, brasil and US have presidents with much more executive powers then the countries from your list ( Kuba and China not because of great executive power because of only one political party making a disagreement in parlament imposible)