Yes, I have heard that same analysis. He can overthrow the government with 150K, but need half a million to hold the country. We had half a million guys in Nam. Locally recruited Ukrainians to enforce Russian rule would probably be as reliable as the ARVN, or the army we “stood up” in Afghanistan.
I’ve seen some videos on social media showing Ukrainians preparing to meet the Russians. They are building blockades out of tires and sand bags and welding tank obstacles out of I-beams. Even older men and women have signed up for the military and are carrying Kalashnikovs. Elsewhere, volunteers are preparing Molotov cocktails in huge numbers.
Russia has a much larger and better equipped military than Ukraine. But tanks are poor urban combat vehicles. If it comes down to street-to-street fighting, which I believe it will, then Russia’s advantage will not be nearly so great.