It really comes down to how you want the G'Quan to play, from screen evidence or as part of the playstyle that you want the Narn to have in ACTA.
On screen, the G'Quan is mostly seen using it's beam... but does that mean that the beam's hyper powered, or that it's the weapon system most commonly in range? The G'Quan v. Primus shoot out showed that the ship is capable of up close brawling, too.
If you want the Narn to be a tough, roll with the punches and keep swinging fleet, then they need a brawler in there, somewhere... if that job goes to that's the G'Quan or the Bin'Tak is pretty much up to how you want to make it. Upping the G'Quan's beam, making the E-Mine a Slow Loader and giving it a few more damage really won't turn it into that style of ship... it'll still be a sniper with a weaker than Omega main beam that will sit at the back and require loads of support from other elements in the fleet to prevent it from being outflanked.
The only real options there are the G'Sten and Rongoth/Rothan, which are both sub-par choices for their PL, the G'Karith or the T'Loth (which isn't as effective at the job as an EA Nova/Olympus or Artemis). Frazis aren't able to reliably deal with a ship that has good AF, and so can't hold the flanks either.
Maybe changing the G'Quonth completely to a Battle Level brawler, or introducing a Raid Level G'Quan varient without the main beam/e-mine but with range 12 burst beams in each arc (say 2 dice each) would do it.
Thing is, no matter what you do at 5 Raid it's not going to be easy to fit a G'Quan and anti-flanking cover in there... and to make it a ship that punches it's weight a 5 dice beam and S/L E-mines would probably be OK if it had good support, but the ships that you can choose for the job really aren't up to it.
Let's look at the Narn list, and split it into Good/Average/Bad for a second (obviously, this is only my opinion based on stats and performance at their role in the fleet compared to other races' ships at the same job):
Code:
Too Good Good OK Bad Ugly
G'Vrahn Ka'Bin'Tak Var'Nic G'Quan G'Sten
Dag'Kar Bin'Tak G'Tal Rothan
Thentus Ka'Tan T'Rann
Ka'Toc Rongoth Sho'Kos
G'Lan T'Rakk G'Quonth
G'Karith T'Loth Gorith
Sho'Kar Frazi
Sho'Kov
Now, that doesn't look that bad at first glance, however, the "good" stuff is at either high PL's, or is extremely specialized. Most of the OK stuff needs lots of support, and most of the stuff you'd want to be doing the supporting is in the Bad or Ugly categories.
Let's compare with the Centauri, for a second...
Code:
Too Good Good OK Bad Ugly
Demos Sulust Elutarian Altarian
Darkner Primus Octurion
Vorchan Secondus Magnus
Liati Dargan Morgrath*
Kutai Maximus
Haven Corvan
Rutarian Adira
Balvarin
Rasik
Sentri
*unless hyperspace is allowed, then it goes to good
As you can see... in my opinion, the Centauri list is a lot better balanced than the Narn one. Ideally, all ships would be in the OK bracket for every race, but going to Good/Bad is OK. Most of the Good/OK Centauri ships are Patrol, Skirmish, Raid or Battle, and they're not great at War.
Given that the majority of games are played at 5 Raid, that is not a problem for them. Also, their lack of boresights and good initiative mean that their ships can effectively operate without much support and still be expected to perform reasonably well.
I don't think the Narn fleet plays like anything other than a flimsy EA fleet with E-Mines and bad secondaries... don't think PnP can really fix the entire fleet, so *overgunning* the G'Quan slightly may be the way forward for now... not breaking it, but making it *good* rather than *Average* if you catch my meaning?