Then again maybe Ranger are that broken ! Will try with my 3rd playthrough.
I still believe mixed is better than all physical without the Ranger in that equation, especially when I see people talking about how 4 two-handed warrior are the best ever group.
If rangers are the issue, then it's more an issue with them than with elemental damage and mages, imo.
It most likely is just a problem with ranged + physical, although until the more recent chicken nerf (haven't tried it since), Rogues were equally good taking out a single target at the start of a fight. They just couldn't bounce from target to target as easily until much later, but they could take out bigger single targets in general faster. They also have nothing comparable to Arrow Storm (which can kill 2-5 enemies in one shot).
Rogues are primarily single target. They can use some multihitting attacks like Cripple and Battle Stomp, but those don't take out groups nearly as fast. Whirlwind can be used too, but the range is too short and you have to be behind all of the enemies to really get much out of it.
Warriors are just, ugh...nothing until midway through Act 2 and they don't start pulling their weight until around level 17+. I honestly don't know what would be worse between 4x Warriors and 4x elemental casters. The Warriors would at least have an easier time with CC, especially if they did a Battle Stomp train. It's just that their magic armor would be relatively so low that all it would take is a boss (with their cheating initiative) to launch 2x AoE attacks like they do at the start to strip you, and then chain CC the group before they can even move).
I actually want to do a 4x Rogue group. The most annoying thing will probably be trying to get 8x good daggers though. I might just settle for 2x Rogues and 2x Warriors.
