Just to be coldly analytical, the impact might be overstated in your analysis. You are assuming a random distribution of casualties, but we know this is not the case.
Putin has avoided using citizens from the politically more powerful segments of Russia. Some populations (such as Dagestan’s) might have 90% of their members experiencing loses, while others (such as St. Petersburg’s) might have 1% or less.
That is true, but I think I underestimate the number of relatives and 15 is probably also too low. But I’m not removing estimated duplicates, of which there are probably more in Dagestan etc.