Unfortunately, there are too many opportunities to convey a fraudulent position.
If the tartan is designed not as the medal but as a tartan for all who served in the conflict, I could almost like it. There are many veterans who served during the Vietnam conflict that did not get in combat time. They are the many that kept the birds ready to fly and the vessels ready to move, the supplies to keep the forces on the move, and the rest of the support, including the massive deforestation (AKA paperwork) that keeps our military running. Each of them served as part of the military and ready to go to the front on a moments notice. They also are veterans worthy of honour.
The problem with much of this is the opportunity to misuse the symbolism. The designer camo clothing that is a part of the urban look that is obviously not military to those who have been there, but not obvious to those who were not.
As a veteran, I cast my vote against the idea, as it would be out of control very quickly as much as I really do like it.

As far as the claim to service, when one has or is not serving, the federal courts have been real good about locking up some of these for impersonating a federal official. Unfortunately, it is only for five years.

my 0.02 USD.
Cheers