Im sure this has been brought up before, but its too easy beating the AI arena defense teams in most cases. And doesnt give you a fair chance to really experience the full effect of your team against ...
It would be nice.. but not everyone have great connection. We will face many lag in pvp battle bcause unstable connection. Then u guess what's next.. exit from battle, retry again, ur attempt battle lost 1, and u have to wait 10 min.
And it could easily abuse.. For instance if i feel i will lose, i just disconnect my data connection or force close the game hmm