I just read a copy of SotG at my local Chapters and I noticed something curious. Apparently the ISDII costs only ~144,000,000 credits, while the DSD costs ~168,000,000 credits. So apparently the New Republic's new SD was more expensive, despite being less crew intensive. The book also said that the DSD was the "ultimate" Star Destroyer, capable of single-handedly taking on any class of large ship (MC series, ISDs, VSDs), 2 medium-sized ships (Majestic-class, Dreadnought, Vindicator) and a whole fleet of small ships (Carracks, Nebs, Gunships, etc...). The key to its success was that it had manoeuvring thrusters along its flanks, making it more nimble than the ISD. The reason why there aren't so many of them is because they're pretty expensive for their size, and I would venture to guess that it's also because the NR military was not exatly making a large expansion after the surrender of the IR.

But of course this didn't happen. We even see MC-80s been built during the NJO when the MC-90 is over a decade old.

I always thought it would be silly to stop producing New Class ships because of the peace, sure you wouldn't need to keep fleet levels as high, but you wouldn't stop producing your more advanced vessels. YOu'd stop producing the older class, such as the Imperial. The ISD should have been stopped after the peace and the Nebula, Defender and Republic Star Destroyers should have taken their berths in construcion yards.

The MC90, as I understand it, is supposed to be a very expensive and HARD TO BUILD flagship. According to the RSB, the MC80s can be popped out at the rate of one every six months.

The MC80B, on the other hand, took from a few months after Endor to two years post Endor (call it 18 months, say?) And they had been building the MC90 Galactic Voyager ever since six months after Endor! They eventually got it around Dark Empire (5-6 years later.)

It's no wonder they decided to try a new strategy. The frigging Executor was built faster than this!

More Republics. Fewer Defenders. Defenders seem notoriously hard to make (even if you add how skimping the NR is on the military.)

I'd also hesitate slightly before thinking of a Defender as superior across the board. Except for its exceptional difficulties in production, it looks more to me to be a ship built to NR doctrine, with a differing set of compromises to match.

It is a ship with a very high tooth-to-teeth ratio, which certainly improves its abilities for a defensive fleet. It is also smaller. It got 80% of the ISD-IIs firepower, but much better shields and better speed (really acceleration in space.)

Tail, however, decides staying power. It seems to me to achieve the increased efficiency, what really happened was that the Defender cut out about 550m of space (with corresponding decreases in width and height) that used to have consumables enough for 6 years. In SW, given the power of the ships, their fuel is an disproportionate burden, and by cutting out over 90% of that, it is very little surprise that it could beat an ISD.

After cutting out the fuel, the next place of attack is the troop complement, which is reduced to about 20% of what it was. Two thousand troops only conquer planets in Star Trek :-)

Between the two, the multi-function, power projection and autonomy of the ship is greatly compromised.

The Defender can afford to give some firepower away to the ISD-II, they carry roughly the same number of fighters and given that NR fighters are general superior to Imperial fighters. You have 6 squads of proton torp/concussion missile carrying craft that can give the Defender the edge in battle.

The NR whoever didn't need this. The NR didn't pacify rebelling worlds, worlds could join and leave the NR at will. If troops were needed it would be a major operation and more then one vessel would be involved and the NR already seemed to have a number of troop transports in service already.

I mean, Fifty Thousand credits was considered as a fortune in RotJ, as Jabba was furious that Bouush wanted that much for Chewbacca. In 2004, a super rich kingpin wouldn't break a sweat if a bounty hunter asked for 50k for a pay.

While it was shown that the Bilbringi Yards were still constucting ISDs, that might have only been so because the construction cheifs knew that they could not spare an entire year to build a DSD when and ISD, a much more common and less specialized design, could probably be built in much less time. This and the fact that the ISD has already been the subject to many variations probably led the NR military to make the "Senator" line of Interdictor Star Destroyers from the ISD frame instead of the DSD.

Also the MC90 was only in development since six months after Endor. That includes making preliminary designs, which would include for the first time (for Mon Calamari) multi-species control consoles, as well as a purely military design from scratch. They did this as well as serve as the NR's primary shipyard until they captured Kuat, and even then KDY was severely damaged. By DE, they had begun an attempt to deliver the MC90 as a Heavy Star Cruiser that could challenge ships like the ISD or even the Allegiance-class without fear. Production was slowed for years after DE because of the damage to the shipyards, but i'm sure that by the NJO the NR must have at least several hundred of these ships in service.