did a lot of implications about GTVA Terran/Vasudan tech similarities, but in the end the Shivans are firing Harbingers and Tsunamis too.
Yes you are right. The similarities are also present in the game. The mentioned Mekhu HL-7/Subach HL-7 similarty. Another one is the GVF Ptah/GTF Pegasus.
So i still think, that there is a vasudan version of the Maxim aswell a vasudan Trebuchet and a vasudan GTF Ares counterpart. Like the mentioned similarities the difference is only small, but it is there. Maybe the vasudan Trebuchet has a shorter range, but is more maneuverable or something like that. Mekhu and Subach are also different only in details, because the Vasudans have their own style to fight.
But i think that this stuff is not in the game, because it is not relevant for it. Because we are playing a terran and most of the time we are part of the terran fleet in the GTVA. Only for a handful of missions on the GVD Psamtik/Memphis

had to create a whole tech tree for the vasudans. Would be nice to have for the immersion, but nothing more. Not really relevant for a commercial game.
The same is the vasudan tech in FS1... it is not really relevant for the official campaigns if the Vasudans have their own counterpart of Avenger, Phoenix V, Athena etc., so there were not created by

I do not believe, that the Vasudans twiddle thumbs only in both games and watches without reaction how the Terrans develop all these new shiny ships and weapons...
Maybe someone like to create a whole vasudan tech for FS1 and FS2 in the future that can be properly used for FreeSpace Port and Blue.
But well, to the original question.
Well, i am not very sure if this war could be won by anyone. It has similarities to the western front in World War I, some of the front systems had back and forth battles since 14 years only.
Even with the Hades, i am not sure if this would be the ultimate end-of-the-vasudan-days-weapon, because without all the shivan tech the Hades would have been a different ship. It would not have any beam cannons, it would not have a superior subspace drive and whatever other tech the Hades only had due to the Shivans. And also we do not have any information about which was neglected for the Hades. Because i think, that all the resources that were put into a super destroyer would have some effects in other aspects of the military.
Maybe the Vasudans would have been able to destroy the Hades right in time. Even in this Shivan enhanced version the Hades had some weaknesses, without it would had surely some more of them. It would not be able to hit the Vasudans from the back, which was the biggest advantage the Hades had in ST:R. Without it, it had to fly through the front lines, without beam weapons. Actually i have doubt, that the Hades would be able to reach the vasudan core systems at all or heavy damaged only.