I'm playing as the UK and I'm level 13. So far, I've put my skill points only into defence and energy on a ratio of 1:2. But is energy really important? Is doing missions even important? Or is it best to put points into attack, defence and stamina on a ratio of 1:1:1? Also, what units should I purchase to give me the best advantage in fights against rivals?
I'm sorry if this has been asked before. I used the search bar, but I couldn't find anything related to my question.