One of the most bizarre things actually is why this vessel would be carrying Sea Killer.
Because it seemed appropriate for a remote and very independent minded Dominion trying to do something different from the mother country.
Remember, this ain't earth we're talking about. Not an AU, more of an AD (alternate dimension) or something. A lot is the same, but there are many things which ain't.
Still, Sea Killer? It has shorter range than surface mode Standard.
I'm all for doing things differently, but at least select a missile that has an advantage over the other missiles you're carrying.
My reason for choosing it are these:
1.) Its different from what the Kingdom uses, and the Dominion which is designing this (Aldeshar) is notoriously stubborn and contrarian.
2.) So, they try to design many things on their own. Sometimes with great success, sometimes not.
3.) This is one of those "not" times.
4.) After a number of years of trying to improve the system, they finally give up and in the mid 90's during the mid-life refit of the cruisers (3 of them in the class), they begin using Imperial missile systems.
The Sea Killer (or, as I have named it in my little fantasy/fictitious universe), the Mongoose, is from the same design bureau and weapons manufacturer who in the 1930's tried to design a "torpedo gun", a triple turret with 21" barrels which were supposed to be able to 'shoot' torpedoes at a target for up to 18,000 yards, at which point the torpedo would then enter the water and continue on to the target. When testing this concept they discovered that many of the torpedos tended to explode in the barrel, which did not endear them to the gun crews, and those that managed to somehow not explode had the flight characteristics of a lopsided brick and exploded upon hitting the water. It was never deployed on board warships, something for which an entire generation of gun crews and their families were thankful.
Hopefully, that gives some background on why I chose a less-than-optimal weapons system for this particular class of cruisers.