Well, it's been a while since I played FS1, but if I remember correctly, the War was not going so well for the GTVA at that point, they had been successful in pushing back the Vasudan Navy right up until the point that they revealed a new class of Destroyer, the Typhoon. As far as I remember, you start FS1 just as the GTVA is on the recoil from having its ass handed to it by the new Vasudan Destroyers.
Edit: I suspect that the weapons are all based on particle acceleration physics, whilst it's not certain, the chances are most races would develop weapons in more or less the same order we did. Kinetic, chemical, hydraulic and electromagnetic energy can all only be used in a certain number of ways, there's only so many designs for a gun that actually work. as it were.