This doesn't happen, if the AI is in formation.
If you order a AI teammember to an postion, he won't leave this position, to get in cover, when he is under fire. For example i told my grenadier, to move to a rock to give me cover, when i walked over a field to a building. When i was on the middle of the field, he told me that enemy infanterie is comming from the left. He started shooting at them. After some shoots, the enemy spotted my grenadier, and started firing back. I was able to see my AI, and i saw how the enemy bullets hit the ground aroung him. Intead of changing his position only 1m behind the rock, he kept his position and died after ca 10sek. Sometimes you have the time and overview, to command your AI to make the small step behind the next cover, but normally you don't have it. Maybe some player don't want their AI to change theis position, because they can't cover you anymore. But normally if you get under fire you will die after a few seconds, when you don't change your pos.
Also if that would be changed, you could use fire suppression meaningful.