Aafes Pogs

They're not "coins", as they aren't issued by a government. The most logical direct ancestor of the military pog money are the military payment certificates, used in the Korea-Vietnam era. And those were definitely paper.

The motivation behind issuing them is of course different. MPCs were primarily issued to prevent soldiers selling military supplies to the locals on the black market. Pogs were issued primarily because the military canteens wished to give out change but didn't want to pay to have truckloads of American coins shipped halfway around the world.

The coin catalogues generally don't list any paper or cardboard items, even ones officially issued by a government and given a coin-like shape, such as certain issues from Spain and Russia. Even the Leyden "siege coins" of 1574 (made from compressed prayer book paper using coin dies - the first ever usage of money made from paper in Europe) are listed in the banknote catalogues rather than the coin catalogues.

As for the collectability of money-pogs: sure. Are they going to make their owners rich one day? Probably not, but if you like them and they are available, why not collect them?