Correct - if the F-35B dies, the F-35C no longer has its flank protected by the Marines and will follow it in short order.
If the Navy could dump the B and C, CV combat capability would improve in the short-to-medium term. Before the B/C would have reached IOC (with full capability, not the Marines' interim capability), the navy could:
- replace lots more classic Hornets with Supers
- start taking delivery of Ultra Bugs with conformal tanks, engine improvements &c
- accelerate the Next Generation Jammer.
And all of this with money to spare.
The Marines would get Supers to replace their F/A-18s (those aircraft, not the Harriers, are first in line to be replaced).
GK121 is right about the C. The big wing is there for CV-compatible approach speed, OEW is massively greater than the A, and the main reason it has greater range is that the gun is replaced by more internal fuel.