This is the plane that inspired my approach for the Space Marine Protean fighters in Nexus Arcana.
www.military.com/daily-news/20… The Space Marines need high-maneuverability craft, and the classic World War II, and Korean War airframes are excellent for dogfighting, while the sleek "delta" airframe is better suited to interception and surface to orbit high-speed flight. This is why the PA-03 Shinden was made. The PA (Protean Aerospace) designation is for defensive fighters intended to fend off invaders, while the PF (Protean Fighter) designation is for variable fighters intended to attack/invade a planet. Unlike Macross, or Gundam, I do not see how any one variable fighter could fill the various mission requirements of planetary, space, and interplanetary combat. A fighter like an Alpha would fit the PF designation, while the VF-01 Valkyre would be a PA, the Zeta Gundam would be a PS (Protean Space fighter) whereas the Delta Gundam would be more of a PI (Protean Interceptor).