My apologies in advance for the newbie question, but I can't seem to find it anywhere in the rules or the forums.
Can the same action card be used for more than one fire group? For example, I have two separate fire groups activated at the same time under one leader; I have one "spray fire" action card to play to supplement my "fire" order. May both fire groups use this action card to supplement the one fire order? I don't think this is possible but would like some verification please. Also, please let me know where this is specified in the rules if possible.
Such cards generally specify that they are for one specific attack. So the answer is "no". E.g. in A40, it talks about "Spray Fire may only be played just prior to the player making a Fire Attack Roll." and the effect on "the attack" and "that single Attack Total."
2 different fire groups are not making the same attack.
Don't confuse the Fire order (which can activate various units, via an activated leader) with individual attacks (which all might result from a single Fire order).