Strongest clan in ELO is either All stars, Ghiest or Skeelz.
Although any deck with Eklore is doing well this week especally Roots,
Havin saying that i think its based on the Banned cards of the week, if Ghumbo and Oshitsune are unbanned then Nightmare rain the stage but thats rare
I'd say Bison is pretty spot on.
All Stars, GHEIST, and Skeelz are all extremely potent in elo.
Nightmare when Ghumbo and Oshistune are free.
Piranas and Montana are great up to around 1300e, they /can/ push higher but they're trickier for it.
Bangers are another one that can push toward the top.