My Ranger is my Rogue (and my maincharacter).
I gave her focus on sneak / pickpoket / lockpicking and let her fight with a bow.
At lvl 6 I invested 1 point in Pyro, so she can summon an elemental.
She is quite good. does average damage and supports my group with her marksman-skills.
My big surprise so far is "Berthold the barrel" who started as a cleric but I found an insane legendary 2hander and great armor, so he is quite a healing tank with a lot of hp and does 150-200 damage per strike at lvl 5
my other 2 chars are mages with 2 schools each. I do not use witchcraft or man-at-arms (except for the first lvl cure)