I started out with the party of 2 casters(hydro+Pyro and aero+geo+witch for the combos during first round), a ranger (pure marksman) and a tank (MAA, 2h and crafting/BS), but after a while I found that the ranger felt both too boring to play, and quite unreliable outside of the special arrows. Since I play on hard my normal shots have too high miss-percentage at mid-max range (I think I hit lvl 8 and even had 10 perception at that time).
I've ended up rerolling the ranger into a pure melee rogue, who actually just carries a bow around just for special arrow usage at pulls. I haven't gotten that far yet with this setup, but it certainly feels much more fun to play, and the dps of a properly built/played meleerogue is insane. I'm still uncertain how she will fare in the eventual cluster****s that I know will happen later on, but it will definitely be fun!
At the moment my biggest question is whether I will sink any points at all into weaponry, or if I should wait for tenebrium on both rogue and tank.