I think it really punishes 3/1 splits. My first endeavor was a group of 2 fighters, a ranger, and a mage. The mage couldn't do shitttttt since he was the only one plinking away at enemies' magic armor.
I don't think 2/2 is so bad, and you do get weapons that involve bonus magic damage (of an element) that'll help a bit. Even so, I rerolled my personal group to be Rogue, Ranger, Cleric and Knight. Going well so far, and feels awesome to pwn the shit out of mages who don't have Phys Armor, but I do dread some future fights with mega badass Rock Golems or some such monster that has massive physical armor and is weak to magic, and my party's just like uhhhhhhhhh anyone got some wands?
My gripe about targeting remains (as j00t highlights), but have you guys noticed two things: 1, the Opportunity Attack icon lies, in that you can mouse back and forth around the edge of an enemy and it'll show and hide the special sword/jagged icon, but if you move juuuuuust outside the range (when the icon does go back to normal) you'll still get hit. This has happened to me in multiple fights. 2, Oil isn't incorporated in the tooltip for movement, IE you can put your mouse beyond a pool of oil and it'll say "2 AP to this point", click, and your guy uses 3 or even 4 fucking AP to get there.