Q u o t e: Ah, good point. A couple of bats would take down a lot of gargoyles, you're right. Now, maybe if carrion swarm didn't cost so much mana, or was less capped, that could provide that extra anti-air?
If the DL went CS over Sleep (Ghoul surrounding) or Vampiric Aura (Ghouls' survival), the strategy wouldn't work in the first place. As a second hero, CS just isn't comparable to FN. It's also an extremely frail strategy to rely on surrounds against a hero that can lose collusion size at the expense of 75 mana.
UD works always start with DK for many, many good reasons. Changing that fact would require re-balancing of almost the entire game. The solution lies in nerfing Orc in a way that only affects the setup vs UD and not Elf or Human. Edit: Pretty much what Zith) just said.