Resin has made some really good work with personal deflector shields (viewtopic.php?f=2&t=6526).
What if we diversify the current shields of the races, without changing the real effect / balance of them? For instance:
UEF:
Current shield mechanics with swallowing everything into the shield.
Aeon:
Reflect a projectile (but with laws of reflection) instead of just swallowing, reduce the damage/velocity of the projectile in the process.
Cybran:
Projectile hitting the shield falls right through with reduced velocity, hitting the ground doing no damage at impact (disabled with EMP)
Seraphim:
Pull the projectiles into the shield generator after it passes the shield. (black hole, antimatter effect)