From what I understand it represents a change in strategy for Russia. They used to drive in a column of armor with a ton of APC’s/tanks drop off a mass of infantry in a group. Ukraine figured out how to turn these columns into a series of smoking ruins and dead/wounded infantry.

Russia has burned through its massive stockpiles of armor. The storage bases are empty. So they are using the armor they have conservatively. They can only use what their industry can produce from new anymore.

Russia is sneaking troops around in small groups at night or when the weather downs drones. Ukraine then has to detect and eliminate them. It’s slower wok.