It’s true that the other techs can be useful(IT for Russia and Germany, LRA for US), but the power of Heavy BMB trumps them all. A bombing run with 3 BMB will take, on average, 31 IPC away. That means Russia, Germany, UK and maybe even Japan would have 0 to spend, and you could slowly crush them after a one time investment of 45. And the run has the potential to take anywhere from 9-54 IPC, but I’d argue that even 15 IPC a turn is enough. What other tech would allow you to wipe out 5 INF, or 3 ARM, or 2 cheap boats, or a fighter, or a BMB every sibgle turn? (And that’s a BAD roll)None. And I haven’t even mentioned a heavy BMB in battle which statistically hits twice every round. Anyway, the point is that with heavy BMB in the official rules you can utterly destroy the enemie’s offensive and defensive capabilities AND damage their ground forces. Try playing a game where you have no income and see how long you last.