Horwath
Legend
The absolute worst would be 4-5 characters that thier players don't enjoy playing. Doesn't matter how thier built.
I think that the premise is that the players play to the best of their abilities and that characters are created optimally. Also that they are team players.
Any party can fail if players play like crap.
5 Rogue Assassins would have crazy alpha strike but little to fall back on afterwards. Being wood elf helps as you can hide in more places.