The standard, and easiest, way to jungle him is with RoB + Tango. It's also decently fast (level 6 around 6:10, bit later if very bad spawn luck, bit earlier if Golems/Big Trolls). Things like QB into two Sobi or Bottle+Crow can be faster, things like Gloves of Haste into Midas can work, but they take a bit more effort to pull off.
That guide is not even close to optimal. And I don't mean in the Necro 3 way at all.