My idea is as follows:
Individually each hitbox chance for ench bot skill, example:
# Settings for Bots Skill 100
MIN_DELAY 0.0
MAX_DELAY 0.1
MIN_TURNSPEED 8.0
MAX_TURNSPEED 15.0
AIM_OFFS_X 3.0
AIM_OFFS_Y 3.0
AIM_OFFS_Z 5.0
HEAR_SHOOTTHRU 100
SEEN_SHOOTTHRU 100
HEAD_ALLOW: 40
CHEST_ALLOW: 30
STOMACH_ALLOW: 20
LEGS_ALLOW: 10
In the above example the new bot will hit 40% in the head 30% in the chest, stomach 20% and legs 10%.
This can make the godlike bot more harder and the newbie bot more easy