I notice on maps like large buildings ai will sometimes not go through doorways and instead walk around the outside of air hangars
They are walking outside of buildings in areas where there are bodies.
Stacks of allied forces bodies should be a caution for ai movement if they are just entering an area.
If there is a tank or machine gun fire in hearing range they should probably be double cautioned.
Likewise programming in some country specific tactical actions if conditionals are met would be useful
For instance in case of a tank, throwing a smoke grenade in front of the tank might be useful if it is equiped. Likewise if an ai has a side angle of advance on a visibly ungaurded tank they should probably attempt to place an explosive charge if they have it.
AI control would be very useful for selecting an offensive or defensive posture rather than just close or spread or standard. For example assault formation, stay in cover when moving, stay in concielment when moving. Other considerations might be move through buildings, stay within building, suppress passages (like doors and windows), probing fire (fires a few rounds and determines if counter fire - using marked points on map within firing range, fire on my mark (units will concentrate fire in the area of a lead character mark enemy point, or allied players nearest mark), hold fire (units will not open fire until cancled or another firing command is given.)
The move within building, move through doorways, tactical breaching (doors windows) movement postures among others, such as stay low, crawl, move through trenches, etc… type commands and the ability for ai to make these tactical considerations if there is no instruction active based on combat phase engagements might make AI less likely to walk into firing squads and kill zones.