Idea is simple. Make heads up display of shield energy bar. What would indicate how much damage your shields can take. And that is sheared whit all shields.
What do i mean. Let's say u have one shield in front and then another in back. Enemy shoots at your front shield and is chips off the overall shields energy bar. Then you turn your back shield the same ting. When your energy bar is empty the shields them self take damage.
I believe that this mechanics would make shields necessary and would prevent the problem what RC has. That is shield spamming.