SinoSoldier
Colonel
USAF Confirms: The Chinese J-20 Spotted In Georgia Is a Mock-Up Used For Training by the U.S. Marine Corps
In all seriousness, what could a poorly-made mockup be useful for? The only logical reason would be A2G target identification or as a prop to simulate parked J-20s.
Meaning that it could indicate that the US plans to destroy J-20s on the ground as its primary means of defeating the J-20 threat. Purely speculation though, and perhaps far-fetched in that sense.