Soldier Power !
The other 3 classes are unbalanced and weak in duels
No point to choose them and in late game soldiers have REALLY REALLY high advantage with this 3/6 levels weapons
Sure If you want to play a resistance build - shooting/vigor + high Toughness + High Reflex - you can do it at each class and you don't care about life bonus or tactics bonus / sure if you make the build RIGHT !! /
But in normal game or every other build with low/no resist - other class is a big disadvantage