AI Missile target choices, AI under missile attack [DEALT WITH]

During one battle with Russia I noticed thier missle units targetted my arqebusers even though they were further out of range than non missle troops.
Is this part of the mod?, how does the AI work out who to target?. If its done by any logic at all or just random/distance from the firer.

I am still generally dissapointed in the way AI handles attack by missile troops. Perhaps its just the animation making it look like they just stand there and take it, which they do. Surely its about time someone tried to handle this by making those units either, move away, go into loose formation, form a shield wall, take cover in woods or something, or charge the enemy. When an AI army has cav units they do go for the missle troops as they should, but many AI armies lack ranged and cav making them extremely vulnerable to my English longbow/bombard based armies.

The battle AI is pretty much just from GrandViz's Ultimate AI 1.6, as that was the best in comparison to the others available.
I agree that the AI should do something when under missile fire, but due to the engine limitations, it would not know whether it should move while under fire regardless of enemy nearby or not, and how close.
They do occassionally move into loose formation however from my observations.

Regarding missile targeting, that seems relatively random, usually targeting the first unit that comes into range. After that, the AI targets the most threatening unit normally, so if you get close with a unit to their missiles, they usually start targeting those. I haven't seen them run after another unit trying to shoot at it if another is closer and more threatening.

In sallies, there seems to be an issue with AI not being loaded properly (and to my knowledge no other mod managed to make it work there either) so that only missiles and cavalry are relatively active while artillery and infantry are relatively passive.

Yes sallies are one of the biggest let downs in the game. Barbarian Invasion attempted to patch it with units moving out of missile range so you couldnt just line the walls with archer units and destoy them, I think in MTWII the start line is much further away than it used to be.
With AI seiges, they use up their available siege equipment and then turn tail.
On one occasion I destroyed 4 rams , every time one was burnt up and they lost most of that unit, they still dispatched another unit to get one of the spare rams and came back for more of the same, it was quite funny.
However in sallies I think the AI misses the point. They don't even attempt to change formation most of the time. Usually infantry arty in the centre and cav on the flank. If i move units out of the base the cav attack that unit which is great if I have some peasant missiles as they skirmish back inside and value per value on unit losses the enemy looses most of thier punch. With the further away start line I do have to move those units quite a way out, so i usually double click inside the base as soon as i see the enemy cav move.
Sallies can often win a war for me if I'm against a large stack(s) as i just sally and eventually wear them down.