Well, ncsswitch, the assumption is that LHTR is NOT being used, nor any of the other common tournament rules, because with delayed tech, a G1 attack on London is just silly.
I really don’t feel it’s a matter of “game over” for the Allies at all, if Germany spent 25+ IPC on tech. Even if Germany spent only 5 on tech, if both players know that a G1 attack on London is possible, you run into the possibliity of 2 USSR fighters in London, which is, I admit, horribly costly for the USSR, but also horribly costly for Germany.
You have infantry, tank, six fighters, and a bomber, going against a bomber, two infantry, artillery, tank, two fighters, and a very important AA gun. Of course, with additional Russian fighters, it looks rather worse for the Germans; I don’t think it should even be attempted in that event.
Depending on the AA gun, and a few bad rolls, and whether or not USSR fighters are in London, most or all of the German air force will be destroyed, and the Germans will hold London with 1 tank.
Now, if the Germans spent all their IPC on tech, they can attack London next turn, at best, with one infantry, one tank, and one bomber. Even if the German Med fleet moved west, it can be blocked from helping in the attack on London by a USSR sub block. Given that the UK can possibly retake on its turn with battleship bombardment and tank from E. Canada, and US can move in to reinforce with 2 inf, 1 art, 1 tank, 1 fighter, and 1 bomber, a repeat of Germany taking London will almost certainly not happen. Either Germany will take Anglo-Egypt with preplaced bid units or not; if it doesn’t, India will be quite strong, if it does not, the UK will very likely be able to retake Anglo-Egypt with 3 infantry and fighter. Germany WILL have 78-82 IPC, but will have next to no air force (if any), which means that the Allied fleet buildup will threaten Germany quite fast. Germany can build a new airforce, but that will be quite expensive, and because Germany spent no IPCs on ground units, USSR can push early (even if it has to retreat later). Germany will also have to commit more forces to trading territories with USSR in the east.
Basically, I think a G1 attack on London is very risky; the initial attack has a decent chance of success, but the Allied counter can easily rock Germany back.
BUT, if Germany only spent 5 IPC on tech, and bought more transports, or some ground units or air force to counter USSR, I think the Germans would have a signficiant advantage.