You will quickly find that the best teams you can make are by using four of the same class - doesn't matter which one. There is little incentive to use a balanced team, and no incentive to use a team with both magic and physical skills.
I was a big fan of Divinity 1, and so had high hopes for number 2. Unfortunately the new game mechanics, while exciting at first glance, put too much emphasis on environmental effects and magic, while leaving physical attacks to be boring an uneventful. Combined with the fact that the most effective teams are 100% magic or 100% physical (as a result of the unrelated armour types), a huge amount of play combinations are overlooked and ineffective. This meant that after many hours of gameplay, I eventually got bored and wasn't committed to completing the game.