Don't waste your time with a conventional assault. You can clear the entire lower part of the board of all enemy forces and post four Emperor Overlord tanks at the bridge leading into the enemy base. It would be hard to force an entry, because eventually hit-and-run rocket buggies combined with MIGS will be too much. It is also too hard to get a sustained air attack through the anti-air defenses and the enemy MIGS will be a continual harassment that is difficult to find a good counter for.
Build your base to the point that you can build a minimum of three Emperor Overlord Tanks, a Nuclear Missile, and a couple Helixes units. Upgrade the Overlords and Helixes with Gatling Cannons. If you can place a single Emperor Overlord on your side of the bridge leading out of your base, it will successfully fend off any ground assault into the base. It's also a good way to quickly train your behemoth up to veteran status. When it reaches that point, rotate the next in. While you're building up and waiting for your forces or missile to get up to strength, use supporting arms (generals powers) to clear any anti-aircraft units from the bottom and right sides of the board up to where the civilian building war factory and tanks are south of the river at the east side of the board.
The basic concept is a well timed helicopter assault. When you have cleared the route, load two veteran emperor overlord tanks into the Helixes. It takes some practice and good timing to pull this off well. Launch your nuclear missile at the bottom right corner of the enemy base so that the fallout area will neutralize enemy forces and clear anti-aircraft for an LZ. With good timing, you want the Helixes to fly along the bottom, turn north, and fly up the eastern edge of the map to arrive in your cleared LZ just as the radiation disappears (for maximum effect). If you can, insert your overlords, fight off the immediate counterattacks and then start working your way north and then west through the base. As you make progressive gains, ensure you're checking on your own base, making repairs, and keeping yourself from getting wiped out. It gets easier if you can wipe out the airfields – then your overlord at the bridge in your own base can fend off everything else.
HH Alternative Method
The basic strategy here is to put 3–5 upgraded overlords on the northern plateau to get relief from the air attacks, meanwhile building eight nukes in your base. It's critical to babysit your hackers and to use lotus to capture derricks and crates for this method to work.
Survive the sneak attack with three bunkers in the area filled with a total of eight rocketmen and two red guard. Build up a war factory and the tech upgrade building and produce three Emperors. Build a Lotus and have her pay for herself by collecting the money crates in the bottom right of the screen, then have her proceed upwards capturing derricks and guns, and getting crates. Don't worry about the derricks getting destroyed. This whole time you should be using your artillery strike to hit the weapons bunkers at the last second.
By now your tanks should be finishing. Build an air field and one helix, then start upgrading the tanks. One at a time, use the helix to ferry the tanks up to the ridge. Spread them out amongst the buildings in the north of that plateau. Start creating hackers. Use hacker money to add two more upgraded emperors to the north plateau.
Build 6–8 nukes in your base, starting midway through the timer on your second weapon reset. Wait until you have six nukes ready. Nuke each command center with one nuke, wait for repair dozer to arrive, nail each with the second nuke. Now you should have time to use the nukes one more time to take out the super weapons.