Some clans are better than others in elo. Playing 4 Pussycats, for example yayoi and Charlie lvl max with Gwen and svelthana lvl min(or lvl man if you have not many clintz) is very efficient. Montanta or Uppers are also very good because of their bonuses.
Sentinels aren't that good for elo cause of the fact that their best cards are 5 stars. most of the good eloer use Pussycats, montanas and Uppers and 2 sakrohms. this is becuase they have a mix of good attack, good damage, great abiliies, good bonuses and low star count having these 5 traits seperates the good cards from the great.