Ignore C&C 4, pretend it never happened
Retconn everything that happened in C&C 4, tell the story from the ending of Kane's Wrath with LEGION/CABAL, Kane and Scrin.
Can officially say that C&C 4 was a mistake, should not have happened and does not count. Will return respectability to the franchise and provide respect to developer studio.
Will provide the basis for a more logical series of events following the ending of Kane's Wrath and allow you to work in the good parts of C&C 4 into the game without completely destroying the core C&C gameplay.