Yes, I agree (to the shooting the same target). Is there anyway to fix that. For any hero, actually. They always turn to the same spot in a battilion, melee or ranged, and try to attack the same thing.
You will be thrilled to hear that the whole setup of arrow and artillery fire has been reworked extensively. Took me about 3 weeks to go through the whole of weapon.ini.
Archers will have a fixed miss ratio (depending on troop qualitiy). The arrows will scatter within a fixed radius (depending on tq as well). They will also NOT follow targets like a heat seeking missile anymore if they actually scored a hit. Only hobbits and artillery had this in their weapons code until now. Furthermore, if they hit another target by chance, it will take damage, even if an allied object. Faster moving objects now have a better chance of evading hits. Large groups will almost always be hit, it's just a matter of which member gets it, hehe.
For Heroes i left it the way it was (100% hitchance, HitStoreTarget = yes).
The thing about everyone targeting the same object has to do with the fact that they attack the closest target indeed. I can't change that, only their accuracy and scatter radius.
Artillery has a much more pronounced and random scatter factor introduced (1.06 already had it, but Mark's Mod didn't, so i copied the codes and made some additional alterations)
Logic Fire (fire munitions setting off area fire) is also quite a bit more pronounced than before. Stray arrows (of which there are now quite a lot) tend to cause grass and trees to burn. Not on all maps though. Not all tree and shrubbery objects used on maps carry a FlammableUpdate and i'm afraid EA did not use logic when distributing those traits. To be fixed at a later date.
So, as you can see, parts of your concerns have been adequately addressed. In Beta 4.5.