Interesting. A couple years ago there was a thread in SPWW2 (
http://forum.shrapnelgames.com/showthread.php?t=38755) where I asked much the same question (post #5). Sigeena's brief yet technically correct reply left me with the erroneous impression that shots remaining made no difference so I've been blasting away during my own turn w/o considering the following half-turn consequences.
Thanks for clearing this up with a detailed explanation. So NOW I know why units were "just sitting there" and didn't fire back during the AI's turn; they'd already used their shots and didn't qualify for more. Which makes perfect sense, since in SP the action is presumed to occur simultaneously even while it's being played out sequentially.
Yet another example of how well this incredible game mimics reality, even if it isn't a perfect "simulation."