As far as I know, there isn't.
But typically, you want TMF, as that single dog does more damage and has more health than all of your other dogs combined.
With Rain of Toads, you should always be able to keep up fetish sycophants. I only summon the fetish army when I'm either starting to build up or otherwise need the extra fetishes.
I haven't seen a lot of high-level (T6+) running a garg. I stopped, and haven't missed it.
The only pet items I have that are great is the MoJ. I rolled some +physical and have a decent amount of +elite damage as well. I'm also only in T3. Any other key pet item would probably get me into T4 at this point.
I'm basing my reasoning off this profile (not mine):
http://eu.battle.net/d3/en/profile/Soilmate-2941/hero/41686349
A reddit builds post for pet doctors (that profile above is the top response):
https://www.reddit.com/r/Diablo3witchdoctors/comments/2faue6
and this guide on reddit:
https://www.reddit.com/r/Diablo3witchdoctors/comments/2faue6
I've always heard that Zuni's is just a stepping stone, not a goal.
I also have one passive different from the "typical" pet doctor, and that's the one with the resurrection (instead of grave injustice) since I'm playing HC. But if you run with grave injustice, you'll be able to bring up the fetish army much more often. And obviously with SMK, you wouldn't need Zuni's at all, as the rest of the set bonuses are kind of garbage. I'm also using leeching dogs since I don't have a TMF.
It also sounds like your TMF didn't roll great? I hate that so much. I think legendaries should be more controlled in what they can roll so that your grinding is at least worth it when you get your first major item.
If you're not already using enforcer, I'd recommend that legendary gem. I have one at Rank 10, and it's a great boost. You shouldn't have to worry so much about keeping up a meat shield with fetishes, as they should just be killing machines.
I might try Zuni's if I ever get a third piece to drop.