The key things you'd like to have on your CB team include: 

- poison damage (or HP burn damage works too)

- healing, revives and defensive buffs like increase defense, strengthen, shield, ally protect, block damage, unkillable, revive on death, as well as the leech debuff

- debuffs: decrease attack, decrease defense and weaken debuffs

- ways to get extra attacks like counterattack buffs, ally attack abilities, speed/turn meter boosts

- last and probably least importantly, offensive buffs like increase attack or just high damage champions

Your roster is indeed very early game and you don't really have ideal choices for most of these roles, but you do have some of them. Your epic Corpse Collector can put poisons as well as leech, which makes her a lock for your CB team for the foreseeable future - probably your best CB champion so far. Maulie is a great champion but not a CB specialist, but since she has a revive and a passive boosting your team's turn meter, you'll also want to use her until you get better options. Galek, again not great for CB but can put decrease defense, so use him until you get better. Spirithost is usable for a while, for her small speed aura and increase attack. And so on.