Leroy, if you're thinking specifically anti- Dilgar, then it largely depends what you're up against.
The two strongest characteristics of the Dilgar fleet are low to medium survivability and very large numbers of medium weapons, for overall high firepower.
Hyperions against them are a suicide's choice. You don't need the beam firepower more than you need an ability to not die.
Hermes, Tethys Missile, Olympus- flash missiles- Artemis, even the Sagittarius. They are your prime choices. Small, heavily armed for thier weight- the Chronos I don't like for it's lack of peak firepower.
Nova vs. Targrath is twin- linked vs. AP Double going up to triple on crits. Who do you think has the edge there? It's a bad plan.
Anything battle or larger- it might work, I wouldn't. Any conceivable EA battle choice, two Targrath will slag far more than half the time, on my table anyway.
If the enemy is assault ships, take fighters- they'll have time to do some damage. Strike cruiser heavy, you'll need to be very lucky to do enough with them to matter before they get in close and gun up your ships.
Best chance is probably to try to beat the Dilgar at their own game- outmaneuver, pack attacks, fast mobile game. The EA is probably the only fleet with low level ships packing enough high level firepower to pull it off. Apparently it can be done with Drazi, too.