Here's the scenario:
The GTA had already been working on experimental shield systems before the attack on Ross 128--the Ross 128 installation had an "energy-based" "deflector array" mentioned in the tech room entry for the MX-50. In this story, the Shivans never come and the GTA's early experiments lead to prootype shield systems, which are distributed to elite squadrons in June of 2335. However, one of the pilots was a traitor who secretly aided the Vasudans. During the trials, he suddenly raced towards the jump node and jumped out of the system into Antares, where his Vasudan contacts were waiting. He gave the shield prototype and his shield-damaging Avenger cannons to the Vasudans. The Vasudans reverse-engineered the shield generator and Avenger and began fitting them to their own fighters and bombers. A new chapter of the T-V War has begun.
In the beginning, only elite pilots will have shield systems. You will fly an unshielded ship with ML-16s, and most of your Vasudan foes will be bereft of shields as well. But early on in the campaign, maybe in the fourth mission, you will stumble upon a combat test of shielded Vasudan ships and their version of the Avenger cannon. Both the Terran and Vasudan military leaders are mortified (but for different reasons), and the war quickly intensifies. Keep in mind that the Thoth and Ulysses will never exist in this scenario, since they're Terran/Vasudan joint ventures.
Terran ships at beginning of campaign:
GTF Apollo
GTF Valkyrie
GTF Hercules (in this campaign, the Herc will have 550 shield hitpoints and 300 hull hitpoints, since most Hercs will be unshielded)
GTB Athena (will probably have less shielding and a stronger hull, since most Athenas will be unshielded)
GTB Medusa (see Athena notes)
GTB Ursa (see Athena notes)
GTC Fenris
GTC Leviathan
GTCv-X Deimos (prototype vessel)
GTD Orion
GTD-X Uhuru (modified Orion with prototype beam cannons)
All FS1 Terran noncombatants
Terran weapons at beginning:
ML-16 Laser
HL-5 Laser (does more damage per shot and fires at a slower rate than the ML-16)
LL-45 Laser (does less damage per shot and fires more rapidly than the ML-16)
Disruptor
Flail
Avenger
Prometheus X (prototype weapon, does less damage than the normal Prometheus that is introduced later)
MX-50
Fury
Firebird (like the Interceptor but slower and does more damage)
Hornet
Phoenix IV (older version of the Phoenix V)
Phoenix III (backwater regions get these clunkers; really sucky anti-bomber missile)
Stiletto
Thor (less powerful bomb than the Cyclops, no shockwave, designed before shield development)
Tsunami
Harbinger X (prototype Harbinger)
Vasudan ships at beginning:
PVF Anubis
PVF Seth
PVF Horus
PVB Osiris
PVB Amun
PVC Aten
PVD Typhon
PVI Cheops
PVI Karnak
All FS1 Vasudan noncombatants
Vasudan weapons at beginning:
VLL-9 Laser (Vasudan Light Laser)
VPC-3 Retribution (Vasudan version of the Avenger; does less damage per shot and fires more rapidly)
VHM-4 Caiman (Vasudan version of the MX-50)
VDM-5 Fang (Vasudan version of the Fury)
VAM-11 Lance (Vasudan Interceptor, faster but does less damage)
VBM-40 Barracuda (Vasudan version of the Phoenix V)
VTM-29 Hammer (Vasudan version of the Tsunami)
VTM-X Nightshade (Vasudan version of the Harbinger, experimental)
VEM-1 EMP missile (it's an EMP missile)
Any takers for this idea?