So, I made a Betazoid science captain specifically because I had a plan in mind for ground combat. I have four klingon science officer BO's with three of the specialising in AOE exposes, two of which also do aoe damage. They all have split beam rifles.
I send them into combat, focus-firing initially but after that, I just let them go on the AI. Klingons have 10% increased threat. They all use their aoe exposes and split beam specials as the very first thing they do, so they're hitting everything.
Betazoids have 20% inherent threat reduction. I do NOTHING. I'm not even out front at the initial attack because I set the position of the boffs ahead of me before sending them in. I just stand there, and yet... I get focus-fired by the enemy.
So, I round a corner and draw them all to me. I then use my sci officer aoe placate. I then die from focus-fire.
If, after all of the above, I can still die from focus-fire, then the ******n aggro system is broken. Fix it.