Akesi Xuni is the elite specialisation mentor for Scourge, when in dialogue with her she says:
'We've refined our art beyond what Joko taught us. Most necromancers defend themselves with their own lifeforce. It seems contrary to me. We use shades instead.'
'An extension of our power, allowing us to affect the near and far, casting spells from both ourselves and our shades. They're versatile, able to protect allies and attack foes.'
Casting spells from the shades and yourself is basically the core mechanic of Scourge, it's part of their identity.
Don't let them destroy us, you may think it's a little change but it is on par with removing portals/teleports from mesmers, or removing kits from Engi's.