I can beat all 7 but this is only because I know how the AI works. Simply make walls (not buildings) for your wallins/path blocking and the CPU will never attack you or your exp's. Make walls walling up the paths, they get stuck and then all you have to deal with are the air AI's. How do you deal with that? Simple. If you cant figure out that much, you shouldnt be calling yourself Player
But if you want to beat the CPU, just use it's weakness in your favor. Walls are your friend vs the AI.
This tactic will work regardless of the map, speed, or resources. Beating CPU's is childs play whether its 1v1 or 1v7. You just have to be smarter than that piece of plastic you call a keyboard
If you want to do it without this tactic, then you're only in for disappointment as there is a cap to the APM in war2 which makes it very difficult if the CPU is unrestricted due to pathing issues. The maps where pathing makes little difference will be the maps that you have major problems with (friends.pud comes to mind). For those maps, just surround your buildings/mines with walls instead. Works just as good as fucking up the pathing. But you'll need a super high APM to pull it off handling 4-7 peons at one time and keeping them making walls while keeping up in res/tech is not as easy as it sounds