I'm a 60 WD currently at Act 2 Belial (Inferno).
From Normal to even halfway through Hell, Garg would be better for you compared to Fetish Army. Reason being is this, Fetish Army has a cool down as well as a time limit as to how long they stay spawned for, meanwhile, Garg will last pretty much forever (or until at least the next CD incase it dies).
When you get to Inferno, Fetish Army can be essential as well compared to Garg. Reason being, Gargs will die in 1-2 hits and for the Fetish Army, they can last up to 6 hits (or however many you have spawned at a time). Each will probably die in 1-2 hits but when you have more numbers taking the hits, that leaves you more time to DPS from the back.
As noted by one of the posters here, Zombie Bears are not mandatory in Inferno. I used to think so too but after Act 1, you will find that you cannot withstand a large amount of time at melee distance vs mobs. I tend to go with Poison Darts and Grasp mainly and it has brought me all the way to Belial.