Gris should be a rogue's best choice. Give her a shield with the perks that benefit from it to make her tough. She needs END and STR the most, with spare points in AGI. Give her a shield that will work best in each given situation, and the best 1H weapon you have for a given situation. By that, I mean elemental, of course. Sonnet or Icicle are good choices, as well as the Red Dragon shield. Tell her to attack on sight, so she takes the brunt of the attacks. I would venture to say her END is the most important skill, because if she dies, it's all on you. A little less damage for a lot more HP seems to be a fair trade.
Your warrior will benefit from a rogue companion greatly. Give him Dungeoneering and a high AGI. Equip him with a Jester's Bow, too. At Level 25, my Adaon does 37.7 DPS, which is damn good for a companion. He also has 85% Disarm Traps and 95% Find Traps/Secrets. If you have that Tiara that gives Detection II and Int +1, use it! Detection I and II both stack. Have Adaon attack on sight, too. The idea is to let Adaon attract the enemies so you can move in and crush them. Since companions come back to life, this adds value to him by doing good fast damage as well as absorbing a good bit.
Finally, I never use the cleric and find her useless. Some build her as an undead killer for certain dungeons, but I never needed it as a 2H Warrior with Adaon at my side.
If you have any more questions, I'd be happy so answer.