T4 fighters and archers that only spawn in Purges used to be stronger than regular T4 fighters and archers. That changed a few patches back, and they’re now weaker overall.
Their damage multiplier is lower.
Some start with slighty higher health, but they gain less health per additional vitality. When levelled, they therefore end up with the same or even lower health.
Purge thralls are much harder to get than regular thralls. It’s weird if the rewards are lower.
Suggestion:
Give them at least the same stats (damage multipliers, health, vitality health bonus) as regular T4 thralls, or maybe a slight bonus such as +10% on starting health to make them somewhat worthwile to get.