Fetish army is really the only mass-summon spell the witch doctor has. The fetish army spell effects are coming along too, it's looking pretty amazing.
But it's really more of an AoE that happens to do its damage by sending out little dudes to fight.
The witch doctor is more about using a small number of summons as damage soaks, and then casting spells for the majority of his damage. Some of which are themselves larger one-off summons. He's not a mass summoner, that's just not the intended flavor of the class.