That's intentional - I am exceedingly familiar with Macross and know the VF-1 back to front. I like the design of the Vf-0 though, so I wanted to use it as one of the main fighters instead of as a prototype. The Sv-51 and the VF-0 would have been visually virtually identical in this setting, but not had the space - related adaptations that full on production variable fighters have.