If you're going to cheat then you have no reason to complain about the ai.
It's not cheating if the game mechanics allow you to do it. How many new players have built more than one merchant, more than one library, or more than one of any other building that you are only supposed to be able to build one of and not realized it? Are they suddenly cheaters for doing it? No. It's a bug, and they probably didn't realize it was a bug. They just clicked the building and built it and then built another one without realizing they were supposed to be limited to one. If the game allows it, you cannot really call it cheating. You might call it a bug. But it is working exactly as it was designed. They drastically nerfed all the items to make it more difficult to make over powered units, but until they change the mechanic, it's not cheating (and right now, it's not even a bug unless you hear a dev say it's not working the way the intended).
I, for one, don't have a problem with the way it works right now. For the costs involved for me to pump one unit up like that, I could have had an entire army of units doing the same kind of damage or even better and not had all my eggs in one basket.
The AI does attack, if you look at it, but the con spawn is so frequent the AIs armies get waylaid on their way to attack you, I've watched it happen dozens of times. Those stacks of shrills or a few dragons and the like make short work of the stacks the AI tends to put together.
Turn down the map difficulty so the MOBs are not quite so powerful and put AI on each opponent on challenging and the AI will do much better.