Um...If I ever let you get that far advanced that you would have that much of a fleet, I messed up and I would give you the win; I would probably let you have the epic battle that you wanted, but would then quickly surrender not to drag it out.
I usually scout and get the phase detection leveled up to 2 jumps away. That way I know what is coming. I have NEVER seen an MP game with a balanced fleet (although the AI does it very well). If I saw a balanced fleet, I would just spam HCs, LRFs, some fighters and maybe a support cruiser here or there. In version 1.09, I don't know yet since I haven't played the beta in over a month, but I would have to laugh if I saw flak in your fleet, they are that ineffective.
In any event, if I know that I was outgunned, I just go and do raids and what not. I love the maruder, I can move faster than you and I am immune to phase jump inhibitors. Anyway, while you are busy chasing me, I would be getting whatever kind of econ/ships I need and hit you on your exposed flank.
If I know I am outgunned, I may also just turtle at some choke points and let the battle come to me. Vasari get damage bonuses in friendly culture, and repair bays are the best defense platform in the game.
My real sticking point with this thread was that people misquoted me. LET ME RESTATE, I AM ALL FOR OUTSPENDING AND HAVING A BETTER ECONOMY, BUT YOU BETTER BE SPENDING IT WISELY AND YOU BETTER BE #1 IN FLEET AND YOUR FLEET BETTER HAVE COUNTERS TO WHAT THE OTHER GUY IS BRINGING. LRFs ARE NOT COUNTERS TO LRFs IN MY BOOK. Too many MP games I end up mopping the floor with people because they spend so much money early game getting their economy up that I have 2x the fleet than they do. For instance, if I am playing a medium 2v2 map and I see that my opponent has 2 civ labs up, I immediately know that I won because while they were paying for those labs, paying to tech ice/volc research, paying for 2 infrastructure upgrades, I've bought 20+ more ships than them. Then I just crush them before they ever make a profit off of all those economy expeditures. If we were playing a 1v1 huge multi star, obviously my strategy would be quite different and I would rush economy.