Getting back to B5...
I always considered it unfortunate that the Hyperion class got called the Hyperion class. EAS Hyperion is simply the first ship of that type that appears on-screen, there is no reason to think she is the name ship of the class. Other fan fiction has suggested 'Rooseveldt' or 'Alpha', but I'd suggest 'Astra' class as the most in keeping with EA naming policy (after Vauxhall cars, hence 'Nova' and 'Omega').
Being serious for a moment, if the original EAS Hyperion was launched in 2216(?), given the on-table life expectancy of Hyperions in the game, it seems...improbable...that the same ship would still be around after forty years and two major wars.
In B5W, the EA went through a progression of weapons - Plasma Cannon, Particle Cannon and (often turret-mounted) Medium Lasers during the Dilgar war, being joined by Pulse Cannon (based on Dilgar Pulsar technology) afterwards, with Heavy Lasers (in limited traverse 'boresight mounts') appearing duiring the Minbari war (purchased from the Narns).
Mongoose seems to have binned pretty much all of this. Which is a pity, since stats for the Hyperion and Nova classes are repeated several times in Armageddon, the opportunity might have been taken to reflect updated models of the ships entering service.
Don't get hung up on firing arcs, they're just an abstraction to make the game playable. Being scientific, there's not much justification for the 'Boresight' arc at all, since there is no reason for a spacecraft to point in the direction it's going (as demonstrated by Garibaldi's Starfury in 'Midnight on the Firing Line').