Sorry but this ain't a rock-paper-scissor type of game. No clan has true advantage over other. Some clan just have better bonus and stats. Try reading the game rules first and the threads at the Strategy forum.
Can you rip them off and sell them at a higher price to your siblings/mum/dad/deceased great grandparents that reside in your house???
but its not a paper-sissors-rock game as jade pointed out, but some clans have more of an advantage to others
nightmare is good against rescue
rescue is pretty good against most clans, especially FPC (not alot of sobs)
sentinel is pretty bad at type one, since their power is in 5 star cards
but also, cards also matter
eg/ if 2 new/bad players had a hand of
marco, alec, hax and kerry (the very best of rescue) played against
k-cube, endora, cell, elixer (some of the bad nightmare), the rescue player would probably win
but if a newb/bad player has the rescue, and a superb, ultimate, wins tornaments every time player had the nightmare hand, the good player might win
so its all got to do with how you play them (which is what merm said, but in a slightly more elaborate way)