I think the biggest problem FS2 had for capship combat was beams. People have a hard time relating numbers to actual lives, even in the real world. 39,000 people were killed (initially) when the first nuclear bomb detonated, according to Wikipedia. Can you really conceive of that? I don't think I can. I don't think any human being can really, truly understand the loss of that many lives.
According to FW, a Hecate is 2174 m long and has a crew of 10,000. Following that, a Fenris at 253 m should have a crew of about 1,163 if the crew scales proportionally. An Aeolus at 272 m should have a little more than that. A Deimos at 717 m should have a crew of about 3,300.
For comparison, a Nimitz-class aircraft carrier (according to wikipedia) is the largest aircraft carrier in the world, has a crew of about 5,700, and is just 340 m long.
So destroying a Fenris is the equivalent to destroying a small town's worth of people. Destroying a Hecate is comparable to destroying two aircraft carriers. The destruction of the Colossus is roughly equivalent to the dropping of the first atomic bomb, and roughly 1/5 the death toll of the second. Yet we see all kinds of examples where an Aeolus is destroyed by a surprise beam salvo or a Fenris/Leviathan is destroyed by a runaway group of bombers. The destruction of the Lysander in the nebula occurs in a matter of seconds, yet represents about 3,300 people lost. Escape pods are never launched except as an afterthought when a Destroyer has nothing else to do.
And space is a lot more volatile medium for humans than water is. Not to mention that the explosion that takes out something that's 2km long has got one hell of a punch. Going back to the "Little Boy" example, the second atomic bomb, the force of the blast was 5psi at 1.6km away from the center of the blast. In Freespace 2, the hull of the ship is vaporized even 1km away from the blast. The only thing keeping anything within firing range alive would seem to be the lack of air around the exploding ship. Unfortunately for the crew in the tightly cramped passages of the ship, they have an abundance of air (for a short while anyway). It would be interesting to calculate if an Orion exploding in the atmosphere of a planet would represent an extinction-level event. Not to mention a Meson bomb...
Now you're trying to convey that scale of loss with an explosion sound and voice acting. The Lysander gets vaporized in ten seconds by a surprise shot from a Ravana's beam cannons. Everybody in the battlegroup has just lost dozens or hundreds of people they knew, just gone. It's really not something that you can really conceive of happening in ten seconds on the scale that it happens in Freespace. Without beams, you'd have several minutes of intense fighting, and then one of the ships would keel over and die. It might still lack any of the true impact it would have, but it would still seem more significant. With beams, a Fenris basically becomes a flying tin coffin for a thousand people.
Mackie makes a snide comment about life being cheap in earlier centuries in Derelict; Life actually seems like it's a whole lot cheaper in the Freespace universe.