R.U.S.E.

This cheevo is rather easy using the same method as I mentioned in the COLLECTOR cheevo solution I did.

Options I set before battle:
USA for myself
I picked USA for the AI
Picked the map BLITZ
I choose the profile for the AI of PROTOTYPE.

I then did the following :

I initially build an airport before anything else. Then I blitzed the 2 sections where my base is and the one just to the left and slightly above. I put down supply depots by the base, the next one slightly up to the left over the river and then a far one on the left side. They are all accessible by the main road that leads over the river to the left of your base. As soon as the airport is built research the paratroopers immediately. Then you need to be quick on this next part. Prepare yourself to drop 3-5 paratrooper units over near the enemy headquarters and their supply depot. About 75% of the time they just started construction of an airport as my guys were dropping out of the planes so I was pretty safe landing them on the ground and capturing the headquarters and their newly constructed airport. Grab the supply depot as well then make some bombers that can take out the rest of the scattered soldiers and maybe a tank or 2.

I was able to win a hard battle this way in 4:07 of battle time.

to do before:
UK-no research on paratroopers
Blitz on AI- never sets up defences just takes tanks and rushes
Map-any large map will work

as soon as you get into the game you take 3-4 paratroopers and land it on their base, after capping the base take all the barracks so they cant take it back, after this take out all the rushing tanks with recon and fighter-bomber planes

A rather easy way to do this is to do the following:

Choose a large map and set it to 2v2. I selected the French as my nation because of their epic Super-Heavy Tank that you can build out of the Prototype base.

Set your one ally as Hard Prototype and give him either the Italian or US nations. (They both work as good Prototype AIs) Then put ONE Hard AI Regular as the enemy. Give him a nation like USSR or Great Britain.

Once the game starts establish a fast and effective supply of resources. Then build a Prototype Base and save up for at least 3 Super-Heavy Tanks and rally them just outside the Prototype Base. The more of the tanks you build the better.

By this time your AI should have done at least some work on the enemy, maybe even giving you a nice lead. Whatever the case, send your Super-Heavy Tanks in the direction of the enemy's bases, picking off his units on the way over. Keep pushing towards the enemy's buildings and keep a good recon team near your Tanks, so that the tanks have maximum range for their weapons. (NOTE: Armored Recon can be built from the Prototype Base as well)

PS: I've done this on multiple maps so as long as the map supports 2v2 you'll be alright. Remember, you need (enemy's score + 70%) to get the achievement. Also, the only thing that can threaten your Super-Heavy Tanks is a massive strafe-run from Fighter-Bombers, which the enemy doesn't figure out early enough to mess up your achievement. Lastly, don't forget to use ruses like Blitz and Radio Silence. Terror and Blitz or Fanatism are a good combination when you're in the enemy's territory.

I hope this helps. If it didn't work for you, please leave a comment saying why and I'll try to help.