Humans already found the answer. It was quite obvious at first, but they didn’t want to admit it. The answer to CL is Spellbreakers. Just like vs any melee strength hero with strong spells. Just like vs Tauren Chieftain. Breakers are immune to impale and steal beetles, rendering the CL useless. They also remove Curse and apply it to UD units.
Ontop of this you can go for heavy Gryphon harass with 1 Dragonhawk to disable UD towers at the expo. Especially on maps like Terenas stand. Human can keep picking off acolytes from the haunted goldmine while UD will be forced to send Fiends to defend. But Gryphon riders are much more mobile, offering HU the ability to creep the map faster and gain an advantage.
This has been employed by many asian players and is one of the reasons not many asians were playing CL in the first place. I recommend checking out Warcraft3Art on youtube, you will find many games from TH000 who has been destroying UD players using the CL.