After Closely monitoring these two great players I believe that ScreaM is the better player. Looking back at their previous matches We can clearly see that ScreaM is constantly carrying his average teammates. On the other hand, if we look at C9 Tenz we see that his impact wasn't as great as ScreaM's. So if we see ScreaM on a better team he'd most likely win everything.
ScreaM > Tenz all the way for me.