I like Krama's team quite a bit. But I would venture to try it like this:
Rhazin: The roly poly lizard does work. Decrease Def AND Weaken, 100% of the time. Hits hard, purely defensive build. Good stuff.
Brago: Increase Defense for your team, Dec Attack for the Clan Boss? Thank you very much.
Brogni: Shields? Healing? Increase Attack? Can block the stun if tuned properly? HP Burn on top of that? Sheesh. Get in that team now!
Kreela: Increase Crit Rate? Increase Attack? Thanks Kreela for letting my build my guys with lower crit rates and huge increases in crit damage! Ally Attack? Wow Kreela, settle down and stop activating every one else's A1 ability like Brogni's HP burn, Narma's Debuff extension, and even Brago and Rhazin's abilities to remove Clan Boss' self buffs. She is an absolute BEAST in my own team
Narma: Get your damage and your poisons on. Narma has poisons, poison sensitivity, debuff extensions for keeping all the fun Dec Def/Weaken/HP burn. Plus she has healing! She will also help to keep Dec Attack up on the Clan Boss at all times. This is really important to sustain through the fight and keep putting damage out round after round
You could, if you were feeling froggy at some point, also toss Ninja in there in place of your two DPS champs. But that is for fun later to see about improvements.
Now you go to DeadWoodJedi's site and look at 1:1 speed tunes for NM and UNM clan boss, plugging in these champs and aligning their speeds so that you can get the right buffs on at the right times to maximize your damage and your survivability. :D