Yes, Marxism is based on a scientific methodology called historical materialism. It’s too complex to be explained in a single comment, but it has an internal logic and methodology which proposes to analyze social systems in general, but especially capitalist societies in particular.
You can’t use the scientific method used in the natural sciences because you can’t put a society in a lab to study it. Social sciences require a methodology apart from the natural sciences, and Marxism has proposed historical materialism, which is very consistent and coherent approach, based on the Hegelian dialectical logic with materialism as a principle.
The article was written by Timofei Sergeitsev, a Russian “philosopher” with no direct link to the government. The article in the website you linked was written in early April 2022, very early after the war, when no one knew what to expect. It was claimed it was “proof” the Russians was intending to genocide Ukrainians.
More than a year later, have we seen anything like it? Have we seen active actions from the Russians to consistently destroy civilian buildings and systematically cause civilian casualties on purpose? I at least haven’t, unless we are talking about a completely different war which I’m not aware. I don’t excuse the Russians of anything, I’m sticking with the facts. The Russians have been very careful not to cause non-military casualties, which is extremely odd for a genocidal regime.
So, in short, it’s your article written by a guy with no links to the government vs. what the actual war itself shows in practice. I prefer to see what practice shows us.