Keep in mind that things like Mass Effect already addressed your complaint in their lore, which is in that case grounded in real-life theory. Namely, firing solutions. Physical weapons don't lose momentum in the vacuum of space, till they hit something or unless they get slowed down by things like gravitational pull. That's why you rely on targeting solutions (which are complex pattern calculations) to ensure you hit something intentionally. Otherwise you might wreck something you never intended to wreck.
That's why the weapons will hit - gunners have reason to check what they're doing (as far as TEC goes, I believe they're using VIs or AIs for such combat functions, and I think the same goes to the Vasari. Advent use the processing power of their Unity).
Adding an accuracy buff/debuff would be the one to incur disbelief, besides balance reasons against it.