This really isn't possible as it would pretty much undermine their lore as far as shanks are just grunts that follow the higher ups. The only thing I don't know is if the Prime's are the top of the chain. As far as I know the Prime's are practically religious figures to the fallen houses, I'm not sure if they are higher than the Kell's though. Thats really the only options. Either the House of Wolve's Kell is not actually dead and will appear in the House of Wolve's dlc and it'll start a giant rebellion in the Reef where all the HoW fallen are subservient to the queen right now and the raid would be you taking down the Kell.