Scenario 1 (Probability 16.67%):
In G1, Germany rolls 1 dice for tech “long distance aircraft” and get 4 (succeed to breakthrough)!
Scenario 2 (Probability 66.5%):
In G1, Germany rolls 6 dice for tech “long distance aircraft” and get 1 dice 4!
In either scenario, the following action German will take shoud definitely be launch an amphibious landing on British, with 2 land units, 1 bomber and 6 fighters! And will more than likely to win.
So for scenario 1, the allies will for sure get no chance. So the game should simply forbide Germany to roll less than 3 dices for LDA in G1, because it will result in either a waste of German money or the allies will concede immediately. Or if Germany insist in strict OOB rule and his or her right to roll tech, just let him or her go and if he or she happen to succeed, it is not very difficult to reset the game.
But scenario 2 is a strategy need more serious treating, because it is a scenario not based on exceesive luck, but on reasonable probability. It amounts Germany gets the tech for free (because it gets all British money), at the cost that Germany has only 10 IPC to this turns purchase. And in B1 and U1, the British and U.S. (if British fails) must try their best to liberate London. By this the German will be released from the western line for one or two turns, though Soviet will be relative aggresive for one more turn than German does not adopt this strategy.