Whether you mount the necros depends on whether you have the hero allowance, with the new ed I'd say don't bother any more
Make sure at the minimum you get a ward save on your general or your seriously screwed, if he dies your army dies. I'd lose the unit of 30 GG and buff your 20 unit to 40, with GWs, horde, and banner of the barrows they can dish out serious hurt, especially if you can put other magical buffs on them.
possibly give one of the CCs balefire.
You should have some points over to get some bats or a scouting vampire to kill war machines, It may not be a thematic but VCs are slow and you risk being shot back to death
Make sure at the minimum you get a ward save on your general or your seriously screwed, if he dies your army dies. I'd lose the unit of 30 GG and buff your 20 unit to 40, with GWs, horde, and banner of the barrows they can dish out serious hurt, especially if you can put other magical buffs on them.
possibly give one of the CCs balefire.
You should have some points over to get some bats or a scouting vampire to kill war machines, It may not be a thematic but VCs are slow and you risk being shot back to death