Allods Online Forum

All classes need similar stats while leveling. Proficiency offensive and bloodlust defensive.
Enemies on leveling maps don't have enough hp to make use of brutality and determination in most cases and bloodlust provides enough self healing. Secondary choice is determination offensive and vitality defensive.

Try to read whole thing, not just few words out of context. I never said brutality doesn't work on mobs.
If you want anything about description then:
150 proficiency increase dmg by 15%
150 brutality description says 0.314% dmg per 1% hp lost.. it means 47.77% hp lost by mob before brutality will be as effective as proficiency. Need to do even more dmg to compensate dps lost before brutality starts to work better than profi.
In most cases (yes, there are exceptions like bosses) mobs die with just few hits (remember - leveling maps where you usually already outlevel everything) so brutality is not very effective compared to profi. Same goes to determination - in most cases fights are not long enough to keep determination bar filled, especially when it comes to somebody new to game without enough experience.

50:50 prof / brut works awesome for leveling
avoid determination, its not viable for leveling in most cases
go highest bloodlust as possbile, you will be always at ~100% health then and heal from doing dmg