DoT in defense team is always higher than in attack team?

I wonder why DoT in defense team is always higher than in offense team. My Proteus max +19 talent, 722 att, mana troop lv17. The opponent’s Proteus max +8 talent, 707 att, critical troop lv13. But their DoT is 456/3 turns, while my DoT is only 408/3 turns. Could you please explain me? Thank Pro.

Ps. I also noticed that the damage of a hero in defense team is always higher damage of the same hero in offense team, even they have approximately att, the targets have approximately def.

2 posts were merged into an existing topic: Understanding DoT (Damage over Time)