It is by no means completely arbirtary! It may be a little off of what it can really do, but it is just used as a gereral guideline. I took the very induvidual stats of each of the weapons that are used by capships, got the damage per second, added that to what you get when you have the velocity divided by ten, and added all that to the range divided by a hundred. I took that number, divided by fiftey, and what I had was the amount of points that one weapon was worth. For flak, slash beams, homing weapons, and heet seeking weapons, I would modify the point values slightly, as to reduce that arbitrariness!
(((dmg•rate)+(velocity/10))[obtional custom operation]+(range/100))/50=Weapon's Point Value
If you add up all the points of the weapons in a ship, add that number to what you get when you take the hull strength of the ship and divide it by five thousand, and then add all that to the number you get when you double the ship's speed in kilometers per hour. That total is the points of the ship. This only works for capships, or a fighter would have the weapons worth, 10 points, plus the hull/5,000, plus the shields/2,000, 11 points total, plus double the speed... 191 points! Wow, an ai fighter could kill a capship by itself! You see, this way of doing things is great for capital ships!
[total weapon points]+(hull/5,000)+(speed•2)=Ship's Point Value