We've all seen Mech Strikes wipe out hundreds of thousands, if not over a million, troops. Mech is devastating in all shapes and forms, and defending against it has always been a huge question. For minimal losses against even the biggest of strikes, you need a only a few things:
1.) TO BE ONLINE!!!!
2.) 1 range setter - trap/abatis/defensive trebuchet
3.) 18k Archer Towers (anyone else see a variation on the Compact Defense)
5.) Defending - 10k Ballista, 10k Catapult
Of course it works with a few less defending mech and ATs, but this is the recommended. If you're running a Compact Defense, simply demo 1 AT and build a trap when you see a Mech Strike coming.
The Premise:
Attacking Mech are slow. They use their range advantage to decimate your troops as they run out to meet them.
Take their targets away... loop out your infantry and cav. Leave ONLY defending Ballista and Catapult (which creep out to meet the attackers at the same speed)
Let your ATs do what they do - rain down ranged death from above. Assuming you have full wall and tech, your AT range is much greater than that of attacking mech, allowing for free rounds of fire before the attacking mech get close enough to do anything:
Here's an example of said theory:
Failed Mech Strike