The intent is to incentivate players to use wardogs for supporting their attacks.
Test done in phase 3: 50 wardogs vs 50 spearmen (no techs) 24 spearmen survived.
some historical references:
The earliest use of war dogs in a battle recorded in classical sources was by Alyattes of Lydia against the Cimmerians around 600 BC. The Lydian dogs killed some invaders and routed others.
Other civilizations used armored dogs to defend caravans or attack enemies. The Spanish conquistadors used armored dogs that had been trained to kill natives