1/4

I just got access to the arena finally but I keep losing. My squad is 2.7 million power. I have 1.3k level 6 troops and most of the people above me have either equal or sometimes lower stats. What am I missing? Most of the time my heroes are even upgraded higher than my opponents. The only thing I can see different is I don't have Kimberly. Kimberly seems always be the strongest. Is not having Kimberly really that detrimental? Or is there something else I am missing? I have Kimberly on my other account so I didn't really want to pay for anything on this one.