Completed the mission on Normal after 2 days of constant fighting. LOL
My winning solution was similar to Tetleytea's idea, I built cheapo fast interceptors on every planet that I conquered and colonised to intercept all incoming DL transports. Problem for me was keeping the interceptors alive long enough to spot the incoming transports. I managed to do it all though with only losing 1 planet to the DLs. I lost another to the Yor but later took it back no probs.
Trick is to see what the DLs are up to... That helps a hell of a lot, you also need to remember some key advice here, ships attack ships, transports attack planets, transports tend to be undefended. You don't need to build up a uber fleet really you just need to defend all your rushed colonised worlds from transports. This means keeping enough money to rush build if necessary. Don't try to go toe to toe with the DLs till you have the upper hand.
Ok lets spell it out for you exactly the ideal plan for victory on normal.
Strategy:
1. Race picks - Economy / Max Speed / Moral & Government - Federalists
The key pick here is speed, the DLs will out run most ships every as but if you can beef up your speed it will seriously help you. You can sometime outrun them, intercept them and rush them. This will help you more than any other pick you can have.
2. Rush colonisation, get all you worlds to rush build starports and colony ships, screw constructors and fighters at the start. Send everything you got to the star ASAP, send the constructors to the top left head corners of each sector to boost range, BUILD military / influence SBs to boost power in those sectors.
3. Rush build Starports on ALL colonises and then farms and industry, you want a viable colony ASAP.
4. Design a small fighter with a sensor module and stick them near the north edges of your space, you want to see what the DL's are up too at all times. Build a cheap 1 laser interceptor and build on all planets.
5. TRADE all tech with your allies. Build all bonus SBs in your home sector only, the rest will only get creamed by the DLs. Use the planet Primus as your MAJOR industry base, it as good bonuses on it. DO NOT let the DL's or anyone else to take this planet.
6. You will most likely not get to the last planet near the Yor in time, I'd actually wouldn't ever try. In fact let the Yor build it up for you and then invade it. The most likely world to fall to the DL invasion is the most northern planet below the DL's sector. They will bum rush that world for sure, by building colonies the DL's attention will be focused on you to start off with. But its only the transports you need to be concerned with. Remember life is cheap in space and losing a ship isn't a problem, its a planet thats a big loss.
7. Build up your tech while watching your allies fight the DL's and you protecting yourself against DL transports. Remember a major flaw in the game means the DL's get a tactic advantage over you in terms of attack. Because you are south of the DLs they great an extra sector of movement over you. Meaning they can attack a range of 5 SQs in a single movement, but you will have to take 2 turns of 5, and 1 to interceptor them. This is due to the stupid notion that all ships must lunch southwards from a planet, this of course means you are 2 SQ further from your target. This also mean your enemy if placed northwards ALWAYS gets an extra movement southwards.
In my last gme this caused me no end of grief.
8. When you hit plasma 3 tech / miniaturization 2 you know its time to hand the DLs their arses. But a medium hull with 6 plasma cannons on it. This will give each ship +12 punching power skip all other components they will only increase the economic drain of each ship. Now build LOADS of them, and I mean loads. A logistics rating of 12 is REALLY essential for a good fleet. Group 3 together to form your first anti-DL fleet. These guys will take down all but a DL battleship if you get the initial attack. You will most likely loose a ship in each engagement but the XPs each surviving ship gains is clearly to your advantage, NEVER try to take on more than one DL or a DL BS. Not yet anyway, after each engagement withdraw to your home sector and assign a new ship to the fleet. This will help the surviving ships gain better XPs and more HPs.
9. Rush research into Phasors. Believe me they will turn this war around for you, up to now defensive technology is bloody pointless. When you get hit for 30 damage on a ship with 16 hps, having -1 defence is just not cost effective. Focus on weapons, more weapons and you initially attacking means the DLs go down faster and means they don't get the chance to fire back. Time your attacks so you have able to get the drop on the DL's if they attack you, you will lose the fleet. With phasors 1 you can upgrade your current design to replace all plasmas with phasors. Trust me it is worth it. All those ships with XPs now armed with Phasors, you wil start to see the actually running from you. They did me.
10. Rush research rapid invasion, you should have at this point already impulse 1-3. They are very very useful on your Interceptors. Build 3 rapid invaders and assign a fleet of Phasor armed mediums hulls to them, now in stead of trying to go directly to the Yor, go via the southern sectors and then when you are beneath the planet head northwards, this may take longer, but guarantees the ships get there in one piece. Trust me I lost no end of ships to the DLs and Yor. Once you are within a Sector distance south of the Yor send in the fleet only, you want to get the Yor to engage you in a chase to lead them away from the planet. NOW this is important, once the Yor defence ships are a good way from the planet and I assume they have no planet in orbit, send in the invaders.
11. The invaders should move in one at a time and a SQ at a time, you want to see what is there before you send all the ships in. Now all rapid invaders should have a speed of 8, thats HALF a sector of space. You can so out run the DLs and the Yor if you have to BUT you need to see them both coming first. Thats where the invaders are very weak, fast but blind. Once the coast is clear RAPIDLY send in all the invaders into orbit, group 2 and invade, using information warfare and you will fail first time, thats why you have 3 invaders there, invade again and you'll win HOPEFULLY!
12. This should pretty much be repeated for all the other worlds. In about a 30 weeks all but the DLs should fall before you.
Hope this helps people.
J