For now I would just use your five best-geared champs. You don't have enough people to pick from to make a dedicated CB team yet, especially not one that is tuned properly. You almost certainly won't be able to make a team that is able to reach NM - again, not without crippling your progression elsewhere.
*Eventually*, you'll likely want Ninja and Tyrant to be on the team, but it's much too early to know for sure, since it will depend a lot on who else you get.
PS - you've already wasted a ton of resources on very questionable champs - Burangiri is okay if only for a few special Doom Tower bosses, but he's definitely not worth investing in this early, and Bonefeather and Veteran are just complete trash. Word of advice - don't just pick random people to level. Only level someone if you know for sure they are going to be valuable on a specific team.
To that end - Sinesha is very good, and Aox can be quite useful too as a support. I wouldn't invest in anyone else yet. Frozen Banshee *may* make it onto a CB team, but especially given you have Ninja, my guess is she won't.