Perhaps the author will respond, he's good that way, but my guess is that it's because Pokey can Feign Death. You might waste your WindUp+Supercharge+WindUp while delivering no damage for the three rounds. This way, you are sure to get in at least some damage, and if he doesn't Feign, you'll kill him anyway.
Because with the additional damage from Rabid Strike, I couldn't guarantee the Iron Starlette would get 3 hits in on Pokey without being faster, and mine is not faster without 2 Powerballs. The windup/supercharge/windup works, too, but I didn't find it as consistent as the Powerball attacks with my breed of Starlette.
I didn't have a Runeforged Servitor so I used the following pets: Iron Starlette (same as above), Clockwork Gnome (1,*,1) and Mechanical Pandaren Dragonling (1,2,*). I followed the strategy until the Starlette died.
I then swapped in my Clockwork Gnome and kept the turrets up while spamming Metal Fist. I wound up not even needing to use my Dragonling!
Very solid strat: used P/S Starlette, the Starlette was still doing big damage til it died right before Enemy #2's Doom went off on me. Servitor mopped the floor with 'em, had 922 HP left at end of fight, plus my 3rd pet riding the bench.