One of the other explanations for the lower death rate in Russia is that they have been doing extensive testing according to Alexander Mercouris.
In Russia, where testing has been very extensive (4.1 million tests up to May 3 in a country with a total population of 144.5 million, with numbers of tests currently in a range of 120,000 and 180,000 a day) the percentage of persons detected in a typical day who are infected with the SARS-CoV-2 virus, but who are not ill with Covid-19, is in the range of 40-50 percent. Many of these persons do eventually fall ill with Covid-19, so the actual percentage infected who do not become ill with Covid-19 is lower.