This game really is all about setting one's priorities.
Unless you're willing to spend hundreds (thousands?) then you cannot do everything. You have to decide what to do and learn to be comfortable ignoring other aspects of the game. The more I play the more I learn not to get stressed about what I'm not doing and learn to enjoy what I am.
And yes- I agree with Thor. Arena is all about getting your fastest heaviest-hitters in the from the get go. Like a street fight you want to hit the opposition so hard and so quickly that you can end it without them even getting an attack in. Hence Phoenix is useless in the Arena.