there is ai avoiding dynamic objects(other characters) in intense (not sure if in intensex or intense pathfinding).

and about ai surrounding player...try with drawing all that on paper and designing the whole code looking at your sketches. it can be very helpful.

about surrounding again...have you considered creating 4 models around player and that they always stays surrounding the player. and when the ai wants to surround him they look for that models and each of them chooses the closest one for example.

have you tried it that way?