I am coming closer and closer to having the script for the fan fic ready. So far we are still a bit unable to clear things up around shields. Here is some more info you can debate on...
A SW vs ST (Star Trek) fan named Lord Poe (Or many other names to do with "Poe") make an excellent and funny series with "The Movies" game called "The Last Bastion". It was set in the time after the Sovereign-class ship (Capatain Picard's Enterprise in "Nemesis" and "First Contact") was built. Due to real world calculations and hours of techno babble (As you might call it) it was confirmed through the SW Attack of the Clones incredible cross sections and the techno babble in the TNG (The Next Generation) series that SW ships clearly serpassed Star Trek ships. The Last Bastion detailed how much damage a single low powerred light turbo laser shot can do to the most advanced ship in all of Starfleet. 1/4 of the Sorverign was destroyed. And that was only a light turbo laser shot. Now, the ST universe is in a very similar time peroid as FS. This fact implies that weaponry might be very similar in strength, along with shields. Speaking of shields... In The Last Bastion, several ST ships were engaging an ISD. The ISD shields were not damaged one bit. After ages of attacking, the ISD was still in perfect health. Repairs were being made to the ISD while the attack was on, meaning that the ST ships were not even disrupting the repairs to the ISD in any way.
Since both these aspects existed mainly during the time peroid of Freespace, then that means shields and weaponry of GTVA ships could be very similar to that of Star Trek ships.
Note: I do not own The Last Bastion series in any way, but it is a very good series and can be found on YouTube. Watch it for a good laugh and some more insight.