Dhe only thing the Russian army can do against the Ukrainians is mass. It has tons of tanks, tons of artillery shells, and now tons of Iranian drones and fresh soldiers. However, according to experts, all this is of poor quality. The tanks are old, their rubber parts have crumbled, the artillery pieces are worn out.
The recruits that Putin drafted are even more inexperienced than any previous ones. Among them are alcoholics and criminals who could endanger their comrades. Maybe they yell around at night or light a fag, which the Ukrainians then use as a target. Nevertheless, quantity has a quality of its own. You can stop tanks with traps, or with tens of thousands of flesh and blood people. You can attack a city with a few remote-controlled missiles or with hundreds of Iranian drones.