There's hilarious amounts of evidence both for and against large portions of their physiology being organic, it almost feels like deliberate misdirection.
because you know when your lead robot scientist is perpetually high on coffee (maybe she needs her caffeine fix which probably post WW3 already have caffeine patches as a 'FING thing or that she just really likes coffee) and has cat ear appendages probably surgically planted on her head.
or I dunno didnt TEAM MICA already explicitly stated that A-dolls can be made for the sole purpose of human reproduction which can also apply to T-dolls if commanders chose to do so...
Lore wise, it's been explained a few times that humanoid soldiers have usage where PR or close proximity to civilians is a problem.
The Army does have "Normal" droid armies. But this makes civlians on edge. A t-doll that simply looks like a girl with a rifle is more accepting. Also in times of Rescue as well. You got a giant robot busting through the wall vs a Woman soldier breaking the door down. and the Civilian is less scared to go with the woman, even if she's a robot.
One example that is in lore is a high class wedding escort. The T-dolls even dress up in typical wedding clothes during the event to blend in with civlians and are always on standby should shit hit the fan.
Also, a lot of the T-dolls we the commander use were technically not ment for military anyway. They were civlian T-dolls doing normal grunt-work like Retail associate, Nurse assistant or maids and stuff. We just got desperate for more soldiers when Sangvis ferris became a problem.
So the civilian T-dolls needed to be program to act more human for easier acclimation to human society. Otherwise, Why have a retail robot with no feelings? Might as well just place up more vending machines if you need a food dispencer.