Another point to consider is the red mining base effect.
That is, the first step in any big war is to kill off the enemy red bases and protect your own. Remember, each fully built-out base adds a +39% factor in attack and defense to every ship everywhere in the galaxy.
The next-most important thing is the green bases, as they boost the economy by +39%. The yellow bases add +39% to morale, and the blue ones +39% to influence. By late game, the research bases are essentially meaningless.
So, if you intend to go to war with a big AI, especially in higher difficulty games, your first strike should be at their red (and green) bases. Similarly, especially in Suicidal, the AIs will send fleet after fleet at your bases. I always base my biggest fleets at or near my most important and most exposed base(s).
The point here is that those AI fleets (even if more logistics numerous than your can be), can be scaled back in power if your red bases live and the AI's die. And, if "all its bases are yours," then the galaxy can be yours .... 
