Remember that the Witch Doctor is using his pets as a distraction..
I'm not so sure of that. He said alooong time ago, in a time were the WD skill tree were different and the own WD was not consolidated.
See the actual Wd skill tree. Theres a entire summon tree filled with buffs to improve your minion power, both offensively and defensively. Whats the point of have a buff that makes your pets frenzied in the last tier if they are not supose to kill anything?
And they plan the Wd to have at least the same amount of the druid's. The mongrel skill can summon up to 5 dogs.