They did the same with AlphaGo back then. First get some "good" player in there to see if they are on the right track. Then get a better player in there. Finally, prepare for a real showdown. In this case it would be ShowTime, Neeb or even some Korean pro (e.g., Stats). Maybe its time to switch matchups and make it PvZ - get Serral and then let's see if the current SC2 champion is good enough to beat this AI.