Super Star Destroyers, love em or hate em, there's a lot of discussion about them and often times people who first play the mod are surprised by them and don't know how to deal with them. So I thought I'd create a thread with my knowledge so far of how to deal with them and how to use them as well.
Since destroying them is what people seem to have more problems with, I'll start out with that.
The first time you encounter a SSD, particularly the Executor class, you're likely to be stunned by the sheer amount of hardpoints the thing has. You will then promptly be stunned again when you realize that ALL of those 100+ hardpoints are WEAPONS batteries. Unlike in base FoC, where the shield generator and engines of a SSD could be destroyed, in Thrawn's Revenge, they cannot. Also unlike in base, though, the SSD does not have a stupidly low population value (I never understood why it was 3 in base, it just made Executor ludicrously overpowered with all its fighters combined with how powerful the ship itself already was on its own). They do still have a large fighter complement however, and this should be taken into account.
The first, and most vital thing to understand about a SSD is while that it boasts more firepower than many fleets, and certainly more shielding (it will take you a few minutes of sustained fire from several capital ships to bring its shields down), it has weaknesses. They are not invulnerable. The biggest weakness of these ships by far is their maneuverability. Or rather, their distinctive lack thereof. These things, for all intents and purposes, basically cannot turn around, and this is severely compounded by their enormous size, which makes it completely impossible for them to maneuver at all on some maps. In addition to this weakness, the sheer number of hardpoints on a SSD means that, by FoC game mechanics, despite its large armor value in the XMLs, each hardpoint might as well be made of paper. They are extremely easy to destroy once their immensely powerful shields go down.
You might be thinking, okay, so what, they don't need to maneuver with how many weapons they have! That brings me to my second point. Much like in descriptions of the ships in established canon, a SSD in Thrawn's Revenge basically cannot hit something that is directly behind it. By far the easiest way to destroy these ships without using some sort of ground to space superweapon is to call in a few, maneuverable ships ahead of your main fleet, and maneuver them into a position where you can call in your main fleet of capital ships BEHIND the SSD, where it is essentially helpless to defend itself.
This is not always possible however, particularly when the ship has an escorting fleet. In these cases, different strategies are called for. Despite what the description says, a SSD is not vulnerable to massed fighter attack. At least, not while its shields are up (once they go down however such attacks are devastating due to their weak armor). However, my favored strategy DOES incorporate a massed fighter attack. My recommendation when you cannot flank a SSD is first to call in your main fleet as one organized body. With luck, the AI will be stupid, and will throw the ship's escort fleet at you, allowing you to destroy it before the SSD can stop turning every which way and come to face your fleet. Once most of the escort fleet has been destroyed, my usual strategy is to send a wave of fighters (not bombers) just ahead of my main fleet. These small, nimble ships will have a better chance of not being hit by the SSDs guns. Their purpose is not so much to cause damage to the SSD as it is to prevent damage to your main fleet and bombers by drawing fire away from said fleet, which should come in shortly after the fighters.
You see, the AI are stupid, and will usually continue to fire on your fighters with a large portion of the SSD's guns, despite the bombers and capital ships being the real threat. Not all of them, but enough to significantly lower damage to your main force. The second part of this strategy is to try to position all of your ships on one side of the SSD so it can only bring half of its weapons to bear on your ships. Additionally, once its shields go down, this allows you to focus fire on weapons on one side of the ship, which once you destroy enough of them, will basically make the ship harmless against your fleet and allow it to finish off the ship with impunity. Note that you will probably still lose some capital ships this way, as the SSD is a massive and extremely powerful ship with a dizzying array of weapons, and even with a large portion of its fire being drawn off, a SSD is still plenty powerful enough to destroy a capital ship.
The strategy for dealing with a super-laser equipped Sovereign or Eclipse class is similar, except you'll probably want to call in corvettes first regardless, to allow the ship to waste its super-laser on them, rather than say, your fleet's admiral, or the Interdictor you should probably have to keep the ship from escaping since their engines cannot be destroyed. Note however that these ships are weaker than the Executor class when the super-laser is not being used, because of the fact that a large portion of ship's power goes into powering the super-laser, less energy can be used on weapons. However do not discount them because of this, they are still very powerful and more than capable of holding their own.