A British Phantom alternative from the Sea Vixen line

Would an indigenous British equivalent to the F-4 Phantom follow the same design path as a proposed Commonwealth aircraft?

Probably not. A British aircraft would more likely evolve from the Sea Vixen development line.

A British Phantom equivalent would probably differ from the suggested Commonwealth design. Continued development from the Sea Vixen family offers the more plausible route, preserving an existing British carrier-aircraft lineage rather than beginning from the same assumptions.