Ok I made some mods to your setup if anyone wants to try it out, here's what I did:
Bunker 1:
2 Super Thumpers
1 Airstrike
2 EMTs
Bunker 2:
3 Airstrikes
2 EMTs
Bunker 3:
4 Airstrikes
1 Time Delay
I replaced the powershields with EMTs because I found they're more effective, and by having 2 on each of the first two bunkers, it's pretty easy to use. I get faster finishes with my setup, feel fry to try it out and modify it, I'll see if some EMTs or the super thumpers can be spared for even more airstrikes.