Since the Awakened Student (from Halloween 2012), Kinak confirmed that there are some opponents that don't just select from their list of technique chains randomly. The Awakened Student would use low-power attacks until it got the "Green Energy Recharge" move, and then use a longer/more powerful chain.
Finally found a second example of this: the Shovel Drone always uses this move set:
- First round: Scoop Closer:Shovel Batter
- All further rounds: Leg Stab:Scoop Closer:Shovel Batter
So we know that the round count matters (Kinak has confirmed this is tracked), and possibly the technique used on the previous round matters.