May want to keep those Tomb Blades together as 6 to increase their survivability/better ensure they get RP
Also consider Lightning Field on the CCB
to increase its survivability, too.
I've gone back and forth on the Tomb blades and scarabs being either 1x6 or 2x3. RP
is not something to be relied on and there are no buffs that make it better to take a bigger unit. Their role in the list is to grab objectives and screen against deep strikes, they cover more ground as two units. The scarabs are in one unit in case I want to use the advance+charge strat but I'm not sure I ever would.
The lightning field is very nice for the CCB
and the Nephrek WL
trait could be good too. I have a veil though so the lightning field will cost me a CP