Russia's entire military strategy. 

Which, unfortunately, works as they have the resources (empoverished people from the "out of sight" parts of Russia and "friendly nations").

Also replacing the back end of the supply structure with North Koreans frees up a lot of resources (keeping the Chechnyans whose job is to keep the Russians at the front or else..). 

Also Russia seems to have built up a massive drone manufacture within the last two years so they are going back to terrorise Ukranian cities (which is a risk-free operation for the Russians).

To be fair, they did try other things too... but the initial smarter approach didn't work out because they underestimated Ukraine. Then they tried to roll over Ukraine with equipment, and now that they've run out of expendable equipment, they're at the 'throwing bodies at it' stage. Either modern warfare is really hard, or Russia is terribly incompetent. I'm guessing it's both.

I'm guessing both. That was basically the USSR's strategy for surviving WWII. If Stalin hadn't had a relatively limitless number of men to throw at the Germans, plus the harsh Russian winter and the pressure from the Western front, the Germans might very well have been able to take Moscow.

I've read that Stalin was also practically petrified for a good while after Germany attacked due to being so terrified of screwing up the whole country so badly. Apparently that would have been a great opportunity for someone else to seize power, but no one dared because of Stalin's earlier purges. Anyway, I don't know if that's true, but sometimes I wonder if Putin's apparent indecisiveness is that or if he just takes his time to consider the options and not act too rashly.

I agree that this seems to have been the Russian strategy since... I don't know, probably even way before WW2. It's definitely not anything new though.

Putin likely considers things more carefully than Stalin did. Stalin had a lot of mental health issues, which were no doubt exacerbated by the position he was in. Putin also has time to carefully consider his actions that Stalin didn't. Putin also has the benefit of a nuclear umbrella and the ability to sell his country's resources to China and India, which Stalin didn't really have. 

Yeah, the Red Army was seriously weakened by the time they reached Berlin. Had the Germans had just a bit more manpower and equipment left by that stage, they could have stopped their march to Berlin at the Seelow Heights.

Speaking of World wars, the current Russian tactics of sending in small groups to find and exploits weakspots and then sending in more troops to exploit them seriously reminds me of the tactics the Germans used during WW1 with their early Sturmtruppen finding and creating weakspots to be exploited by regular troops afterwards.

That tactics actually works very well. The key is those groups are plain clothes men (no uniforms, no visible weaponry) which intermingle with the local people (many of which are Russia friendly in the eastern regios) while doing their spywork.