They can be used in ELO and deadly if opponent doesn't hv DR/SoB in their hand. I commonly (doesn't mean always) seen Piranas in ELO because their bonus is universal and hv great support cards + pillz manip too.. Other than their SoB which can stop Junta's bonus, their only DR is Calliope..
La Junta is the clan that their best card doesn't get ELO banned, Isatis get voted sometimes, but not always like Bogdan.
Remeber that Junta has best pillz reducer, Naginata, powerful Isatis, Arnie can finish the fight too, and get ur pillz back if it doesn't work. and don't forget Trish. She's scary if u don't hv SoA/ Protect: Power.
I'm just trying to help, but note that I never played La Junta, most of the times I use Freaks, Pussycats and Vortex.
I'll give u some recommendations for ELO Deck:
Thormund, Scotty, Sabia, Milena, Trish, Bryan, Isatis/Arnie, Naginata