Being able to sneak while fighting is a great thing, however it leads to two situations:
- Hit / sneak / hit / sneak and get away with most battles. That's a cheese, although the only thing to make it possible to beat the first act with only one character.
- Some ennemy abilities somehow just know where our character is. Phoenix dive, the teleportation from the crocodile (although this was just dumb, teleporting back and forth around me while not breaking my stealth), most aoe spells in fact. This leads either to fighting from afar (where they don't see us) or trying to take down those priority targets to win the battle.
The second, the auto-targeting of invisible characters, is clearly a bad thing. How would they know ? That's not the solution to the sneak cheese.
The first needs a bit of polish. The AI should for example at least move to the last location the character was seen, forcing some movement and thoughts about how the ennemy would move without detecting us - although we would probably need to be more mobile (either more movement/AP or more movement spells that don't break stealth).