Technological inventions connect like a web. There is a reason James Burke named his show “Connections”. We can move the goal post for any given invention wherever we like, really. If V-2 wasn’t invented for the military, then we can simply move the goalpost such that we mean another type of rocket, but make sure not to move it sideways such that the invention could be used as a transport propellant or for signalling.

But I wish to step aside now and acknowledge how silly this whole argument is—as most arguments are when it comes to alternate history. Historically the military has been the most well funded of all government enterprises so it should come as no surprise that many innovations happen under such well funded programs. But that does not mean that is the only possible outcome. Humans kept innovating and inventing even as funds were diverted to non-violent endeavors. Today we have universities which are well funded and engage in research, often handing out their gathered knowledge to the rest of humanity (James Webb space telescope can attest to this). Who know what we would have invented already if it wasn’t for the military taking most of the attention of historic societies?

You can’t really compare solid fuel rockets with liquid fueled rockets. And rockets fed by turbopumps (unlike the earlier pressure-fed models made by Goddard and others) are in a class of their own.