My buddy and I have tried simultaneous shooting.
Here's how we've set it up:
1. Army A executes all shooting attacks. Army B records the number and type of hits on each of its units.
2. Army B executes all shooting attacks. Army A records the number and type of hits on each of its units.
3. Both armies execute all Run moves in alternating order (Army A runs one unit, Army B runs one unit, and so on).
3. Army B makes all saving throws and removes casualties, takes leadership and pinning tests, falls back, etc., as normal.
3. Army A makes all saving throws and removes casualties, takes leadership and pinning tests, falls back, etc., as normal.
This seems more realistic--in real life battles, shooting happens more or less simultaneously. The approach also avoids several major problems, particularly the dreaded Alpha strike.
Does anyone have any opinions or suggestions?