In that sense it is fast, but turns don't equal actual time. A speedy deck can almost finish a whole match while you perform the 40+ actions for the combo finish. Plus it goes through the four turns much quicker, because there are less actions and card selection going on.
So you need to get to turn 4 (fast deck wins the first match). You perform the combo (fast deck wins the second match).
So you need to get to turn 4 (fast deck wins the first match). You perform the combo (fast deck wins the second match).