Well...yes, it's technically exactly that.
But it's not just a random selection of 1% of the people. It's 1% of people from a fairly restricted demographic (18 to 30 year old men) that they've focused on for frontline troops (there are older recruits, but the majority are in that younger bracket).
So, looked at that way, the loss of a million men *from that demographic* represents a loss of...BOTE calculation here...the life expectancy is abuot 70 years (maybe less, but close enough for a BOTE), which means 18 to 30 is a 1/6 span of the ages if the distribution is somewhat even. It won't be, I acknowledge, but it'll give us a ballpark figure.
So 1/6 of Russian men is about 12 million men more or less. Of whom a million are gone.
That's about 8% of the cohort.
Those are fairly big numbers. 1 in 12 men in the 18-30 demographic gone is a lot.
It's less than 1 sixth, because the population is not evenly spread. The median age is around 40, and there's a definite shrinkage of the population pyramid below age 35.
Which means that it's actually a greater percentage of the younger population. Some people are bandying about numbers as high as 1 in 8.