VF-19A is a carbon copy of the YF-19 really. It's designed for mass production. Don't know if the F and S is only designed for space use, they looked fine when the M7 fleet got to Rax. Thinking about the variants, the kai had some adjustments too when it got to Macross 7, assuming we went from YF-19 to VF-19 Kai. Cause of the wings, that is the next closest relative to the YF-19 I reckon, followed by the VF-19 F and S.