I have never seen this behavior, but In the current combat implementation I don't know why you would not individual steath your characters into combat and keep your wizard in high ground/range. I can't think of a combat in the game where this is not possible.
This is fine, if you already know where the fight is going to be and where the creatures are. First play through, where it's highly likely you are going to stumble into combat walking down a road, this isn't always possible. The ancient temple is a perfect example. The fight with the bandits inside the temple, there is no high ground, and stealthing is fine, but they overwhelm you quickly. If you need to reload 2-3 times just to get through a combat, I don't think that is a good design.
Another issue. This happened to me as well. Party member goes down, enemy is standing next to downed party member and the fighter. Enemy decides to attack the downed party member. In a real situation, or even in d&d pnp, the fighter is the more immediate target. Why would the enemy attack a character that is already downed, when there are others threatening it?
Again, just some AI tweaking.
