Training is clearly more important than Berzerker, and ECM and Combat Sensors are more important than training...
...except...
players don't have to choose between them - they can get all of them, and they add together linearly
...
...except...
they can't develop Berzerker, or Aggressiveness/Defensiveness, during play, and except for Racial advantages, all the material bonuses and training eventually level out so everyone has the same thing, which means that the player who took the most racial combat advantages will have an advantage throughout the game, and particularly at the end.
PvK