Advanced Polonian Barracks is the upgraded infantry training site of Polonians. Apart from basic infantry squads, they can also train their exclusive Machine-gunners and exoskeleton. It is also capable training the Weapon Systems which they are operated by engineers when they roll out of the barracks.
The medic station of this upgraded barracks is now a comfy wooden shack instead of a tent. Other sleeping tents are also larger than the basic version, possibly for housing more back-up soldiers and weapons.