So I've been spending some time trying to complete the campaign and exploration and custom and the others and have come across this problem. The deal is to beat 4 insane terran comps using 3 computer teammates. I've used different race combinations and the outcome is always the same. The 4 insane terrans alwaayss mass MMM and stay together, where as my team attacks randomly with the units they have, very frustrating. Any help on how to beat them or a good strat would be greatly appriciated.
I did all protoss and used a map where each computer has separate bases. I just did a 2gate into 4gate and kept pumping stuff. Follow an ally when he goes out to attack, you should overwhelm him. Usually the AI doesn't help much if at all. I think maps where the AI has a shared base makes it ridiculously hard. Btw I did each 'beat four x comps' with four of another race to hit two birds with one stone, it worked just fine.
By far the simplest way to do this one is to play protoss on the mega something map (4v4 two giant bases with 4 apiece). Start mining immediately, and send 1 probe to the wide ramp of the other base. Build probes up to max supply, and by the time you get your probe to the other base u can build a pylon. Then forge, then start cannoning out from that central point. You will destroy at least 2 bases and your allies will take care of the rest. Just make sure to cannon out in an even pattern and dont waste money. Once you get one cannon within range of a cc its enough, and you move in a different direction. Just make sure that you build probes until you have about 20 so you are brining in optimum minerals.