If there is something like this and I just don't know it, I apologize.
My problem with setting artillery is that when I have more than one spotter/foo I tend to lose time when setting artillery. I will try to explain.
Let's say I have 10 artillery pieces, and 3 spotters. I pick spotter (a) and use artillery units 1-4 to shoot somewhere, I do the same with the rest.
After a few turns, unless I keep using the same artillery for the same observer and same target, I will find myself directing fire for one or more of my artillery with a different observer, by accident.
I hope I am clear so far.
For the artillery bombing screen, what I suggest, if possible, to either have a button which shows the target of the artillery, without telling the artillery to use the current observer.
Or, have, perhaps text, next to each artillery, the designation of the current observer.
I have no idea if I am clear enough with this.