I've once heard of someone finishing that campaign by rushing the Dread Lords' planet with cheap fighters (I imagine this was to lure away their ships so the planet becomes undefended) and many, many transports. However that was only on Tough difficulty.
The thing is very few people have played the campaigns, even less after ToA came out since it made some of those campaigns nearly impossibly hard.

The thing is that if you look closely on their ships, they almost never put defensive modules (shields, PD, armor, etc.) on their ships.

Therefore, if you attack them with ships that are quite heavy on the weapons and maybe a few defense points of your choice, then you can beat them if you keep on chucking out ships like no tomorrow.

Hey guess what! 

I got up to that mission too! 

I'll play it tomorrow and see how difficult it is!

Update: Hmm... A Lot tougher than I first thought.

I mainly got by using luck mostly.

I have my civilization get itself some creativity and hope that it would kick in at a great moment.

That moment is when it instantly completed the Large Scale Building tech, enabling me to build Battleships.

And it also kicked in when I'm researching Advanced Logistics, so I was able to pound the Dread Lords into the ground.

I knew I was somewhat cheating using the Creativity but I was thoroughly annoyed by the DLs by the end.

You want help on completing the mission?

Well I have not played that mission (yet). But cracking open the map and senario files I can give you a general plan:

So, you start out in area 1 with a standard force of ships (survey, miner, colony, scout) and one special ship, the Anorian Battle Cruiser (going to be referred as the ABC). I assume it is a very powerful ship (It should be anyway). This is good because the Yor start out with a rather large amount of ships in areas 2-6. Closer inspections on the name suggest all of them have missiles and PD. Keep that in mind as you research your weapons and defenses of choice.

Starting off you have a basic load-out of technology except one thing crucial: Planetary Invasion. You are obviously going to need that in order to beat the Yor. In your first turn, start researching Xeno Economics. On your home planet, rush buy a recruitment center and start building only two factories. In your starport, rush build a Radar Station. If you do not have such a design, I suggest you to go to the ship yard and design one. It is basically a cargo hull with alot of sensors attached to it. This ship will help provide advance warning should the Yor attack. Once you get to the main space screen, set your survey and miner ships to auto and send your colony ship to the nearest planet next to your starting planet. Develop this planet by rush building a recruitment center and building at most two factories as well as a starport. Keep your ABC close since even though it is powerful, it is possible you could lose it and it will hurt your mission gravely.

In the next turn, your Radar Station should be done. Move the ABC and the Radar Station towards the location marked by the yellow X. Set the Radar Station to Guard mode once it arrives. That way, if it sees enemies, the screen will center onto the station and it should show you enemies. Keep your ABC close by to attack the enemies. Then, rush buy the starport on your second planet and also rush by a Small Hull Ship with weapons of your choice. After it is completed, send it to the ABC and form a fleet with the two of them.

Develop your planets and patiently wait until you build up a sizable attack force consisting of your ABC and more fighters. Send a few fleets to attack area 2 and eliminate all ships in the area. Assuming the Yor did not snatch up the planets there, send in a colony ship or two to claim and develop them. Station your fleets next to the Yor planet in area 2 and make sure no ship gets built there. Blow up the Yor Mining starbase in area 2 (if there is one) and also destroy the asteroid mining bases if the Yor has them.

Once you obtain Planetary Invasion, build a transport and send it to the Yor planet in area 2. they should fall. After that, keep on playing and you will eventually win. I made a suggested route for you to take when attacking but the way you go about the mission is up to you.

On the note on abilities, I suggest you max out economics mainly so you can develop your economy easier. Everything else if up to you but I would invest in better weapons ability to enhance the performance of the ABC.

Hope this helps!

Rush buying is buying a ship or building in 1 week rather than waiting for construction to finish. For buildings, you need to select it in your building queue and click the "buy" button at the bottom of the screen, see for example this screenshot:

Similar for ships, when you click the "build ship" button in the top-right, you'll get a new screen that includes a button "purchase".

Approval on a certain planet is influenced by 3 main factors: size of the population, level of taxes and any morale buildings. On top of that you have galactic wonders and technologies that give a boost to morale. If you're being invaded, get that recruitment center that dnzrx mentioned, maybe add a farm once you reach your population limit and add a few morale buildings or alternatively lower taxes so that approval is rising.

Can't you use the ABC to intercept enemy transports? If you need it for other purposes, make sure to have a few cheap ships on each of your planets: enemy transports without attacking ships will not be able to invade (and can be destroyed by your cheap ships), in case of attacking ships it buys you some time until your ABC can join the fight.

To invade planets with high population, 2 ways work best: use the option mass drivers during invasion or use the bottom option that will convince part of the population to fight with you (this is only effective if the planet has low morale)

I got a question for dnzrx, how do you play the custom maps? And I do have a certain build order on planets, i'll post that as well.

Of course the capital city place.

Starport.

Entertainment center.

2 Factories.

2 Research centers.

Entertainment Center.

If any more tiles, 2 Market Place.

Entertainment Center.

Anything wrong here? Also, do I talk alot?

First of all, calm down.

Second of all, can you post the error message you are getting here? I can not determine the cause of the problem without the error message.

Hmm, I do not know.

Maybe it is a hardware problem?

I do not know the solution. Go ask someone who might know.

Sorry.