From my personal point of view, the trick is in having so much experience in the format that you have a deeper knowledge as to exactly how many pillz your opponents will play on any and every type of card.
Also, there is another factor.
Most of these low star cards can indeed beat many high star cards. Let's say your opponent has drawn some really powerful cards, such as Pilzken and Isatis. Powerhouses, right?
Yet both of them die to Space Hans Ld.
You don't secure victory by winning 3 rounds, you secure a lot of points for the DT You should play low * card that beat most 4* and 5* pill per pill or even playing fewer pillz like Mim, Raser Ld, Aamir, etc. so you don't have to perfect pill and predict your opponents