If the enemy has 9 capital ships then you need 12 imo. At least match them on carriers, but have more if possible.
From the sounds of things, you need at least 2 of each capital ship, 60+ carriers, 20+ flaks, 50+ HC's and a mixture of the others. Some Robot ships will help with hull repair, Dunovs with shield repair.
Also, how are you for research ? Have you researched all the shield and hull and gun upgrades yet ? Have you upgraded the Capitals to level 3 at least and assigned their ability points to the most useful ? Dunov with shield repair and everything else with their biggest extra gun or missiles. Do you have a mix of capitals or all the same one ? I always try to have equal numbers of the capitals so the abilites are all present.
Tactics wise, take out at least 2 of their capital ships as soon as possible. Select all ships, and right click on the icon for the capital ship nearest the jump in point (and try to be aware of where they are and place your jump in accordingly) and just keep right clicking that ship every 5 seconds or so until its dead, then shift target. If you take out enough capital ships, they will retreat. (If you click a target once and then leave it, they will all reselect their default targets pretty soon and ignore your target, so keep reclicking it.)
Do they have a nano weapon structure ? If yes, target this first and destroy it before you do anything else. One of these alone can nueter your whole fleet long enough for it to be trashed without firing a shot.
Also, if they have several repair structures in the combat zone, you may need to take these out. Alt-select your bombers and have them attack the repair structures.
