ORIGINAL: brian brian
you don't simply retreat straight back to the Urals. you carefully choose which units the Axis can attack, and where. the goal is to keep your HQ (even rail moving the slow ones) and ARM and MECH as long as you possibly can, hopefully all the way back to the valley south of the Caucasus and the Volga line in front of the Urals. At those points you have to turn and fight even with the armor. But before that you need to trade in your GARR and INF for railing out factories and impulses of Axis time (and some MIL, but over-reliance on weak MIL can make things too easy for the Germans; it is also key to scrap your 3 and 4 factor units after they are lost). keeping your ARM and MECH alive is a matter of managing your fighter cover well to help keep them from getting ground-struck, and just generally keeping them out of range of the Stukas at least. To do that you have to move them backwards, which is a retreat. two ARM/MECH units in a clear hex, outside of Stuka range, are a strong defense, especially when they can only be attacked from two hexes, and are unlikely to even be attacked while the Axis is also busy reducing your cities full of infantry. all that changes as soon as those tanks are without enough Fighter cover and within range of too many Axis bombers - watch carefully for strong Axis LND3.
trying to maintain a strong solid line in front of the Axis for too long allows them to use their air superiority and blitz bonuses (smart Panzer commanders change Shatter results to Retreat results to keep the Russian units from the safety of the production spiral) to destroy your units too fast for you to replace them. you will lose units no matter what; the key is to keep your best units until the Axis forces start to thin out as they have to divide their efforts on to the many strategic axes that are key to the long-term Russian defense - Leningrad, Archangel, the rail lines to the Urals (Saratov and Kuybyshev are key hexes now), the Turkish border and then Baku, and the Crimea.
and once the front stabilizes on those various axes, yes it is true that Russia is resource limited. key aids then are convoys in the Caspian, factories in Murmansk and Baku (for Persian Gulf / Suez resource and BP deliveries from the Western Allies), and also factories railed to Archangel to run off saved oil while the port is frozen (thanks Composer99). It also helps to store 8 oil in Leningrad to keep producing during the siege.
saved oil is a big help to the Russians in lots of places and ways. one saved in Rostov with the Koniev HQ might make the difference between a successful Axis attack and another turn of a large German force stuck on trying to clear the hex. an oil in Sevastopol will give the Axis concern about it someday fueling Russian aircraft for runs at Ploesti (an historic fear of Hitler's). a saved oil in Vladivostok can keep the Russian SUB threat against the Japanese alive. as much oil as you can sock away in Siberia can help keep those railed factories building units. and lastly, the West can ship in as much oil as they can build a convoy line for over each summer to the major port at Archangel.
Have a bit more patience with newbies. Of course some of them act dumb -- they're often students, for heaven's sake. - Terry Pratchett