I noticed the Empire side doesn't have a shield slot for most ships, while the Rebel side does. The Empire ships have higher base hulls for the ships that don't have shield slots, but is it enough to offset the advantage of the shields?
I've looked this up before, and found out this. To balance out the shield dilemma, Ties have a special ability called power conversion. You can instantly give a burst of power to engines or weapons. giving it to weapons instantly fills the energy guage, allowing you to give sustained fire. This slows you down, and decreases your mobility. Giving it to engines fills up your boost instantly allowing you to speed away. Republic ships can divert power too, but power conversion gives you an instant maximum burst.
Hope this helps. :)