Bots start not full of mana?

[Ikeren]

Cleric bot: 85% is wrong. They're using Hand of Conviction, which costs 3200 mana. Your cleric bots would have to have 21000 mana for a cast of HoC to take 15%.

For them to drop down to 12% mana after buffing makes sense: Hand of Conviction + Blessing of Devotion + (Resist buffs? Is that in the cleric spell list).

What you're seeing is a change from bad calculations to accurate ones. I won't specifically run numbers from every class, but I'm betting that is what it is; bots previously used NPC mana calculations which gave them significantly more mana then a PC of the same or worse equippment. Now they use PC calculations, which means less mana.