I want to say the raider, for a number of reasons;
1) it was produced earlier in galactic history, meaning it would probably have more established production lines, meaning there would be more of them to defect or easier for secondary ship yards to produce with, and this is somewhat important in terms of production, less lead time. The ability to put a project into production quickly, while still taking into account local resource needs and manpower requirements would be vitally important for the fledgling pentastar alignment
2) Its smaller with what I assume to be a smaller crew compliment - I know this might seem counter intuitive in terms of effectiveness but that would mean it would place less stress on logistics & manpower making it an easier choice for commanders. Not only that but a smaller hull generally means less resource usage, When Grand Moff Ardus Kaine splintered from the empire he would have had to make hard choices in terms of production capability, and go for cheaper ships which is indicative of the munificent class - which is somewhat obsolete
3) The fact that the article specifies that there are different versions of the vessel indicates its popularity, and its modify-ability. With the raider it would be easy for a commander to grab a defected Raider I and swap out the hardpoints with AG-2G laser cannons. The AG-2G while admittedly produced by Corellia, would still be available on the black market in large numbers. (
http://starwars.wikia.com/wiki/AG-2G_quad_laser_cannon/Legends). While the vigil is also modifiable, the tactical thinking, and size, of the vigil means it is generally put into production as a pocket carrier or small command ship
4) The articles specifies that "
Considered useful in the Outer Rim Territories by the Empire due to its hyperdrive" meaning that there would be more of them on the outer rim territories which is Kaine's prime recruiting ground. Being able to acquire a ship and a crew with experience in that ship class and type, means you can dilute your manpower between experienced spacers and newly trained recruits, when new ships are built, without loosing to much effectiveness too much.
5) If you go by Exodus version of the Vigil class (found here
http://starwars-exodus.wikia.com/wiki/Vigil-class_Corvette) The vigil class is more a multipurpose pocket carrier rather than dedicated anti star fighter support, and while no doubt it could be reconfigured that way I would still argue that the size makes them a pocket carrier, or a patrol, command and control system, rather than dedicated anti-starfighter support.
6) Kaine is a old hand - he was one of the earliest supporters of the Emperor, he rose up through the ranks, and is experienced in matters of business and logistics, politics and naval warfare, because of this he probably would've stuck with what he knew worked. What's more Kaine's isolationist policies means he would not have had access to technology produced after Endor, except that which he could steal, bought, bribe or blackmail, the fact that he heavily relies on victory I's rather than type II's is indicative of this.
Feel free to argue any of these points
I'll try to reply whenever I can.
Meo
