I could do that myself now: make a copy of core, change the PoW formula, and presto: a hard fork happened, and the coin has split. If the 1000 PH/s is not important, what is the difference between my bitcoin and their bitcoin?
For a start, the PoW.
After that, it depends.
Depends on what? If the hashpower is not important, and preserving the PoW is not important, then what is the magic factor that would cause all the value to go to the CoreCoin branch instead of the CartelCoin branch?