Step 8 of the NMA card description:
Remove any Generals left without Brigades.
Remove from the game, or "remove" to the unemployed generals box?
Does this include the Royalist general who comes on for Lord Herbert?
You remove them to the Unemployed Generals box, just like the procedure in 8.2. That includes Lord Herbert. The only reason this is called out as a separate step is that the players have a chance to shuffle around some forces before having to remove Generals from the map, so it's called out separately, but the procedure is identical to 8.2.