The staff do try balancing each of the clans. The Survivor Meta is being redefined almost every month or so due to new releases.
I do think all the clans have the potential for greatness in Survivor.
Roots and GHEIST are great because they block abilities
Attack Manipulators are also good for low Pillz fights, especially up in the higher zones.
Raptors can help overcome the conventional tactics.
With Bangers or Ulu Watu, a lot use Ambre or John Doom in their decks and win the rounds they can overpower the opponents in. Similarly, if you have good All Star Cards such as Roderick, Weifang, Harrow Ld, Jeremy François, use them.
Nightmare prevents conventional bonuses from working.
Pay attention to what your opponent uses too. If a certain clan appears to dominate Survivor, change your deck to counter said clan.
I feel you need to be using at least 4 different clans (5 including Leader) to stand a chance overall in Survivor when pitted against different clans.
However, I am sure you will figure it out once you play more in Survivor. Hopefully you will find your answer.
Good luck in Survivor.
If you only want 1 deck I'd pick skeelz since the newer skeelz cards are so much better than the majority of the old ones and that the cards are all arounders you got pwr manipulation, atk manipulation, poison, toxic, heal, regen, -pills, +pills, etc. The main special thing that change is skeelz get slightly more powerful abilities than others or slightly better/stable stats balancing out their bonus which is both super strong and super weak at the same time since they can stop the dreaded soa and ignore sob, but is 100% unless to every other bonus in the game.
Montana is still a fan favorite
T1: Roots, Uppers, Sakrhom, Frozn
T2: same clans as T1 + Hive
Those clans have the strongest cards, best synergy for Survivor and are easier to play, but considering how many OP cards have been released recently for each clan you can get a good streak with almost any clan