The Cleric Advanced Skill Guardian Wolf is useful if utilized effectively. Good use of Guardian Wolf can include pairing it with the skill Flames of Faith, and/ or Battle Prayer. Or, using the summon wolf as secondary damage source to help gang-up on enemies. Also can help buy a few seconds of relief in a fight when you need those cool downs to complete.
BUT, for your exact question, I'm not sure Guardian Wolf by itself is very helpful in the Arc. It might help with some damage here and there, might keep the spiders at bay for a second or two, but for the most part, Heavy Hand, or Duel, might serve you better, as stated above.
Clerics can do well in the Arc do to their healing ability. They just need to survive a few trips to start gathering Arc gear. Keep in mind Steel Wizards hit with pure shock damage, so keeping your shock damage high helps a lot.
Support Clerics that relay on party members doing damage might struggle as the most of the Arc is a solo-run for your character. For those builds, Guardian Wolf might be useful.