Hello, at first i should say that english is not my native , so excuse me about that. I use Cu as tank, because when well trained , autohealing and healing you , but they dont delivery so much dmg.
I used to do the next: at first raise all resist to reach 75 (wich is cap ), then add many points to try to reach HP (2000) or close, 3rd place increase stamina, usefull to dont be stuck and speed, last increase int and dmg.
keep in mind when your pet die there are a 25 % chance to suffer stats loss, so , i usually save some points (100 or close) to repair this stats and resist in case.
I hope this info be usefull for you. Good luck