Well, the chance of you getting any Blood Frenzy if you run 3 in your opening hand is 37%, and getting one by turn 3 is 46%. The reason the suggestion for 6 total draw cards (4 Blood Frenzy + 2...

You only have 3 Blood Frenzy and no supplemental draw.

-2 Smashing Blow

+1 Blood Frenzy
+1 Crippling Blow

You need two more draw options, most likely Tainted Oracle. My first thought is to...