The essential point, to me, isn't the exact detail of their age, but the harrowing experience of being naive country bumping thrown into a situation wildly beyond their control and stumbling through while playing catch up. I am not getting my hopes up that the show will be able to fully convey the subtlextual, personal & mythological thematic of being sent to Vietnam as a young man at the heart of the story...but I hope they try.
They can do a lot with perspective and camera techniques. A lot depends if they drop into first person perspective or not. I would like them too but I’m not sure anything in the trailers I’ve seen suggests they will. They may be keeping it as a surprise or for later though.