However there are a few combos for physical char's as well one of the best combo in game was for example DecayingTouch with FirstAid.
I really hope they made that decaying touch only damage for 100% instead of 175%.
I disagree with mixed group, however, I know many players have stated this but I have a lot more fun with a mixed party and it's very efficient.
When an enemy warrior with a 2handed aproaches, my casters will take care of him because he has very low magic armor. In the mean time my Physical classes will hunt the ones with low Armor.
But yeah in EA many players would say, just focus your group on one type of damage.