Ukraine

Is it safe to assume the vast majority of Russian soldiers are males between 19-30?

If so, based on the population breakdown that I looked up, Russias casualties are just under 10% of their entire population in that demographic in the first year of this conflict.
I don't think so.

https://meduza.io/en/feature/2024/1...line-soldiers-say-grandpas-aren-t-fit-for-war
Another senior official from the mayor’s office confirmed that in recent months, volunteers over 45 have made up about half of all recruits in Moscow. However, he didn’t see any issue with older people heading to the front. “So what? They’re fit, they’re fathers,” he said. “They’ve got experience and can outperform any [young] guy.”

But the lawmaker sources had a different view. According to these soldiers, the older servicemen “can’t keep up” — they struggle to carry heavy packs and dig trenches. “And they’re sick. They’re all sick,” one soldier wrote. “Their legs hurt, their heads ache, and they’re slow.”

Throughout the war, the Russian authorities have repeatedly introduced measures to expand the age range for conscription and contract service. In the summer of 2023, the maximum draft age was raised from 27 to 30. Additionally, a new regulation increased the age limit for reservists by five years, raising the upper age limit for reserve service from 35 to 40 for first-class personnel, from 45 to 50 for second-class personnel, and from 50 to 55 for third-class personnel. Last year, the upper age limit for contract soldiers was also raised — from 65 to 70.

I heard between the dead and the fled Russia will have a massive problem in the not-too-distant future. But one hears lots of things which don't really pan out as expected.