Merranvo,
Something along those lines I was working on a little while back - the main prob as you know is precise targeting.
As suggested one could possibly achieve a good simulation of one enemy shooting at another by precise control of their respective relative rotational positions whilst attaching at least one of them to a path, thus ensureing if placed correctly that they face directly towards each other when firing their weapon.
Of course this has very limited usees in specific tightly controlled scenarios.
A far cry (theres that term again) from real enemy or ally decision making but would fit the bill in a specialised situation. Of course even then one would need find a way of achieving health reduction from hits and the resultant one killing the other or a workaround trick to simulate such.
Worth all the effort perhaps, but I doubt it.
Truly there is not going to be a substitute for even a simple default method of character targeting involving some kind of group recognition that could be supplied by TGC or someone else in updating FPSC.
Lee without doubt is the best person to do this if anyone can and I am quite sure he could if he so desired.
"I am and forever will be your friend"