Oh I'm not saying it won't work; the turrets will still track and fire well enough. But from building a similar turret to your missile launcher in a model of mine some time ago, the barrels do a small bobble when they are trying to track, and don't actually point at their target when they lock on. Your missile launcher (very cool launcher, by the way) may have its tubes too close together to notice the bobble, and it may not even happen all of the time. They still look and fire in the right general direction, it's just another odd behavior that comes out when you break the very specific rules of turret behavior.
That said, I actually think WC had similar turret restrictions, (except that they didn't have to be placed with normals strictly up or down), because every turret I can remember seeing on a ship in that series comformed to the horizontal row rule.