A brief recap of what I've tried. I've concluded that the key here is to get rid of the Oracle base asap. Since they keep sending cruisers at me if I don't destroy them immediately, and the destroyers the Keeper sends to their base pass through my base and wreak havoc while cruising through. So at the start, I send the two bombers on the west edge of the map to the Oracle base, and build two more and send them there as well. The other two bombers I send to take the planets closest to them. The freighter I send for a metal=>oil trade run starting from the asteroid at the top of the map. My bombers usually manage to destroy the Oracle base (Usually = If Oracle doesn't build assassins for base defense. Sometimes he builds just assasins, sometimes just interceptors, and sometimes both). If I win, i might have 2-4 bombers alive, and I send them to take the blue planet. After that it's just a race to build assasins to deal with the ships headed for my base. I lose the planets quickly to enemy forces, and I move the bombers to safety. My freighter keeps getting shot at, so I have to fix it after each run, and after the first run I just go for a metal run, since there is a Keeper assassin at the red planet.
At some point when I have enough assassins, I send most of them and all available bombers to the Redog base (I keep the one that started from the NE corner near the Keeper base, as it wouldn't stand a chance getting anywhere else). I have to keep some base defense, and my only income at this point is scavenging ships flying to or by my base, since I don't have enough ships to take and hold any asteroids or planets. The Redog base falls, and I send my remaining ships to take the planet nearby, and repair for the next assault. If I have bombers left, they'll go sit in a safe spot near the keeper base. I'll reinforce my fleet, and take the keeper base. At this point, my base is down to about 20 armor. The Swarm starts swarming me with scavengers, and I try get any available ships to their base. And I never get there with a fleet that has any chance of destroying them... My results so far: 4 times I've run out of time getting to the swarm base, and 2 times I have tried to attack, but my forces have been to weak. And there hasn't been much time to reinforce or repair as my base is normally down to about 1-3 armor by the time my fleet get's there.
Now this is my most succesful strategy. I've tried others too, but nothing worked as well as this. I'm off to bed now, but hopefully someone could shove me in the right direction so I could finally beat this level tomorrow... Is there a solution that doesn't rely on shear luck? I'm strating to think that these last few levels need more luck than tactics
And I seem to be fresh out of luck 
