All you need to do to beat 100 and under (and even most that are higher) is to scout what they're building.
If its barracks/hall, keep scouting until you see what units. Spam tanks/hornets depending on what they build.
If its VD/factory, spam hornets
If its Airpad/Summit, spam hornets/marines/hogs.
WIN!!!
Anyway, the only problem you should have is if they are Covy and rush you. Mine's at 120 and when they rush, it is annoying! I fend them off successfully, only for them to come back 4 mins later with 20 wraiths. OMG!!!
Rushing ALWAYS works against AIs. They are completely hopeless at fending off Covy leader rushes!!! Mwahahahahahaha!!!
Everything is overpowered!!!