Template I am working on, but will take me a while is 3x WD and a monk. I think a barb will work as well but the monk provides the mob clumping superior to anyone. When they all bunch together the pets stay with you and the gargs just cleave through everything.

Use a standard 2.4 LoN garg WD build, and a support Globe monk. One of the passives will be Gruesome feast for 50% more damage uptime.

The biggest issue I'll be running into is most likely survivability. Currently I run through TX with ease and everything feels like a oneshot and I don't have any characters with the LoN set just Helltooth.
Big Bad Voodoo is where this team will shine, mix the 3 stackable runes together and you should have close to 100% uptime giving 60% IAS and 30% more damage. The IAS is the key as it will unlock the next breakpoint chain that most teams never achieve.
Right now BBV + Task and Theo gives the Garg a 54 point breakpoint, an extra 40% IAS should deliver it down to the next breakpoint and I'd guess it might even hit the next breakpoint after that if you throw in the monk using Transgression to add another 10%.
All the DPS is coming from the Gargs and they hit extremely hard. With my non optimal gear I see 11 billion crits from just 1.

So train of the thought and limited testing, the monk does any amazing job clumping the mobs and keeping the pets close by due to the clumping. The Gargs cleave it all. Surviving will be the big question, Barb offers perma 50% DR but I haven't been able to test out channeling bats yet which gives 25% + 30% DR.