I used to play computer games about WW 2, an especially good one is the German attack on Russia. Computer games can be useful in giving on a good sense of where cities are, what terrain is like "roughly", and what forces are present. It's of course very possible, not really easy, to beat the computer playing either side.
Guderian wrote a book after the war that folks like Liddel Hart supported (and vice versa) that Germany would have won except for Hitler's mistakes. It was pretty self serving and I can recommend (again) the book entitled "Barbarosa" by Clark. Guderian claimed if this and if that they could have won in 1941, or at least captured Moscow. Napoleon of course did capture Moscow, but it wasn't a rail and manufacturing hub at that time as it was in 1941.
The Wehrmacht knocked out more divisions in 1941 than they estimated Russia had, and more were on the way. The Russian divisions of course were generally not well trained and initially not well equipped, but there were a lot of them. In the computer game, the German player can go about anywhere he wants, mostly limited by logistics, but he can't go everywhere at once, you have to pick and choose. If you pick perfectly, which one figures out after playing a number of times, you win. Wars are far from perfect things.
Speaking of the V2 project, Germany also built an aircraft carrier, almost complete, during the war. The effort is probably equal to maybe 20 submarines. Instead of the V2 maybe they could have made ~300 Panther tanks, or more, but they were obviously becoming short on manpower, and FUEL. That was a war about fuel, mostly, it's why Japan attacked PH in 1941. It's why Hitler wanted the Caucusus in 1942. It's why the middle east was largely a British fiefdom.
An interesting scenario is Hitler doesn't attack Russia in 1941 but gives Rommel enough support to knock the Brits out of Egypt, thus opening access to the ME oil fields, and perhaps bringing Turkey into the conflict, or going up into the Caucusus through Iran (geographically tough). India likely falls at some point, Japan gets the entirety of coastal Asia, and things are different.
But Hitler of course always had Russia in his mind.
There also was a V3 under construction, partially built, a long fixed in place artillery piece meant to strike London. That would have been ... bad.