Red+Green She-Hulk

Hey, we haven't even got a grey She-Hulk yet! Barring the brief cameo in Sensational She-Hulk when Jen goes to the Balonyverse, reverts to human and changes into a huge savage grey Hulk at night, a problem that persists until she goes to some radioactive spa - when she reverts to Sensational size but still grey and then everything gets reverted at the end of the issue...

I'm aware you're being rhetorical with your question but my answer would be - because she's her own character... and it's getting to the stage when even some fanboys don't go "HULK RIP-OFF!" So... copying a Hulk storyline would be a setback.