Against the AIs, I've done that.
The key, I suppose, is to develop your planets well.
Grab stellar manip 1 for monoliths, pick up resource converters, and run down the planet utilization tree.
Make all your planets breathable 255% value worlds with monoliths pumping out 20 systems worth of resources, and you'll be ok.
Dump mines on your warppoints, and stack your ships up behind them.
Get your maintenance reduction up as high as possible.
Take religious tech for the combat shrines, and the nature shrine. The talisman can help too
