OK, had my first invasion last night. I was on the receiving end. I had a significant troop advantage (~5:1) but what looked like a tech disadvantage (~1:2). No attack or defense advantages either way. Result: *almost* all enemy troops killed, but all ours were killed so we lost the planet.

So the question is what goes into the tech advantage number? I hope it is not just a sum of all techs including those related to farming, diplomacy, etc and only focuses instead on comparing the military techs. Is that correct? Thanks.