TR doesn't need to build anything either (I actually find it slower for TR to build, because you need to get the minions into the pit too), and would have equal if not better killtimes, to be honest (Don't yet have MM). BUT TR is better suited to farm multiple giants at once because of innate penetration of basic attacks (along with AoE during banshee), and being able to tank through the massive damage stabs, again thanks to banshee.