1) the vehicles nedeed to be micromanaged step by step, it seemed they enjoy to expose their back to the enemy
I've noticed this with the SAF units too and brought this up soon after Hooper was released. I don't think it was ever addressed.
1 or 2 vehicles out of every platoon can't seem to stay focused in the enemy direction or drive around in little circles.
2) mortars were linked to a mech unit, how to link them to another unit? Also, after moving them forward they had no ammo and did not fire for the rest of the battle...should not they slowly recollect from ammoboxes?
I try to never move the mortars after placement because I have no idea how far they can move from the ammo and how long it would take to refurbish according to the distance. I have seen them refurbish from the ammo boxes if I moved them 50 meters from the ammo but never tried to move them further away then that for fear of them never firing again.
You can try disbanding the mortars and they will go to the reinforcement pool then attach them to the Company or Battalion HQ platoons.