i Think there's something wrong with the AI. They are, as you say, far too kind. The reaction fire is deadly; and I like the firing algorithm... but come their turn they stand there like dummies, similar to what I heard about 'overwatch freeze' in the remake. They apparently can't decide what to do when soldiers are watching them
suggestion:
if uninjured, fire at closest/least armored/highest ranking soldier, or throw grenade (do psi if applicable)
if injured, based on 'aggression', run for cover or choose above,
I loved it in the original when they had a clear shot but instead scurried away, it left me thinking "what the... WHAT ARE THEY DOING THAT'S MORE IMPORTANT THAN SHOOTING MY DUDES!!1" it was spooky.
Latest: my guys were right around a corner (2nd floor Abductor) from the Floater Leader armed w/ plasma rifle. I snuck a guy in behind him and gave it a stun but it stayed up (and didn't react if poss.). End turn and it floated around the corner, moving only 2 tiles, and then stood there staring at another three of us... gave it another stun & it dropped.
( faceful of hot plasma, pls.
_~