Knockdown shields and other ideas

One of the biggest problems in the games is the amount of time it take to revive someone. Knockdown shields should serve another purpose, they should also determine how fast you revive a teammate. If you have a purple knockdown shield then the time it takes you to revive your teammate should be shorter than if I had blue knockdown shield and blue knockdown shield should be faster than if I had a white knockdown shield. You could even add a red and gold colored knockdown shields and maybe they revive with more health or shields, it would make the game more interesting in certain situations.