What exactly is the problem here? It has a ship system that does work on beams, and a hullmod that boosts the range of the otherwise-quite-short non-beams. Even though beam builds are currently meta, the ship can run non-beam energy's such as autopulse or even mining blaster just fine.
In terms of viability for fleet combat: very strong. With the Onslaught at 40 DP, Executor at 50 DP is still good. Excellent shield, better than average speed for a heavy battleship, large missiles, and a fantastic weapon combo (ballistics + LARGE energy slots is so much better than medium because ballistics have the best anti-shield and don't care about slot size, while large energy has the best anti-armor). It's ship system is one that benefits hugely from system expertise because it is charge based, so it can benefit from Sys+Missile AI officers or a high skill player.
The only downside of the ship is low base flux. That is partially dealt with by skills, but does constrain the weapons. Either low-flux or high efficiency weapons are a must - plasma cannons are right out, and IR Autolances or Gravitons go well in the medium energies.