i  included  a  photo   of  pretty  much  all  my  relevant  toons.  

Am  I  barking  up  the  right  tree  here?  Or  am  i  missing  a  clearly  superior  team  comp?  

Kael has to go, obviously. Sinesha isn't great in CB either, as good as she is elsewhere - one healing ability every 5/6 turns isn't exactly enough to earn her a spot on your team. 

Vrask and Apothecary could be worth a shot as replacements, yes. I don't see that much value in Catacomb Councilor - other than his ally attack he's pretty bad. Fayne is also a very good CB champ but she doesn't bring that much that you don't already have from Tayrel, Nethril and Zavia - only the weaken, really. And keep in mind the 10 debuff maximum, you may already have more than enough poison with Nethril and Zavia as it is.

thats  a  good  point  about  cat  council.  I  guess  i  was  overly  attached  to  his  ally  attack  ability.  Zavia  and  Nethril  already  max  out   poisons  on  occasion  as  it  is,  so  an  ally  attack  honestly  wouldn't  do  too  much.   Thanks  for  the  input.  

reliq tender is a beast cleanses and heals esp where ur at at the moment in terms of cb and progression 

apothecary is great too but once you start speed tuning apothecary throws any speed tune out the window 

id try reliq first to see if her in team (obv need her higher than 40 at 50 should still help) and drop sinesha.  Plus she revives also