You should use only 6* champs at CB, if possible, as they will do a ton of damage from Warmaster/Giant Slayer masterie, even if their main job is being a healer.

You mentioned only 4 champs in the team you think about. But as you saied "two main poisoners", I believe the unnamed champ is Gravechill Killer. I think Skullcrusher is even better. His counterattack will push your damage a lot. First your team attacks, and after that, when the CB uses his AoE, your team (counter)attacks again. Especially with Vrask as healer this is also a second heal for your team.

Skullcrusher, Frozen Banshee, Vrask, Rearguard Sergeant, Coffin Smasher.

Skadi  thanks  for  your  info,  yes  sorry  i  meant  to  say  gravechill  killer  for  the  poison  synergy  with  banshee.

but  you  think  skullcrusher  would  be  better  ?  

so  as  you  suggest  my  best  team  would  be  skullcrusher ,  banshee ,  vrask ,  reargeard ,  coffin  smasher?  

vrask  is  better  than  doompriest?  More  heal  but  lacks  removal  od  de buffs.

skullcrusher

doompriest

banshee

coffinsmasher

vogoth

100%  this.  

You  think  doompriest  and  vogoth  is  better  than  vrask  and  seargant  is  better  in  this  team  for  cb?

Wont  i  be  needing  the  seargant  dmg  reduction ,  heal     and  better  heal  from  vrask  vs   doompriest  and  vogoth?  Or  will  i  benefit  more  from  doompriest  and  vogoth  in  this  case?

I  also  have  stag  knight  but  i  assume  he  doesnt  replace  anyone  i  have  on  my  list .