US military personnel is down to looting locals - they have no money recognised as such in 300AD. Of course, there are beads and other trinkets to barter with the DTs ...
Most US military personnel are nominally Christians - and all belong to sects yet to be invented, in some cases over 1500 years into the future. Some sects are just around the corner, though ...
As the locals have already used a few passing mentions to invent murky concepts like e.g. the Trinity and are eagerly killing one another over details of the Nature of Christ they will eagerly wrap their minds around even more convulted ideas like the Holy Wafer, Predestination, etc.
Lots of fun!