Actually, it would probably best if they just use the current model, but copy the battle options from "Reach for the Stars!". Basically in that game when two fleets meet up, during each round of combat, you get to select your tactic: Short, Medium, Long Range, or Retreat. Then, whoever has the faster engines get to use their tactics. So if you chose short range, and he chose long range, but you are faster, the combat will happen at short range. This goes rather well with what you suggest about which weapon works best at what range. This adds a second dimention to the rock, paper, scissor game that may very well be worth pursuing.
Also, when you chose retreat, if you are faster, you are able to retreat first, as opposed to getting shot before being able to retreat. The only problem I see with this method in GalCiv is that when you retreat, you can just attack again if you have movement, which may be a bad thing, as it probably means many retreating battles. At the same time, however, it might be a good tactic to draw out a battle, mimicking a fast scout that keeps running away from combat, or the intentional luring away of combat ships so you can sneak attack with another.
There are definitely many simple, subtle adjustments that can make the combat more interesting, this range option, the ability to cloak so you can hit first, etc. However, as much as I would like for them to be in the game, it might not be wise to implement them at the moment because of various issues with how the AI will have to handle those tactics. Perhaps sometime down the line, or in the expansion pack, after the team has gotten some sleep.
