Two champions you have been sleeping on:

Drexthar Bloodtwin - +70 ACC leader, HP Burn on A1 and on being hit, self heal, needs no books

Lightsworn - decrease ATK, AoE increase DEF, AoE revive on death

Use more DEF based champions if you can.

You could make an unkillable team with Maneater and Pain Keeper (see https://www.deadwoodjedi.com/speed-tunes-4/New-Budget-Maneater---3-Bosses%2C-1-Comp ). Then you can also forget about decrease attack, healing, increase defense, revive etc. Although it does take a lot of gear tinkering and stat tinkering - and even now, I still have trouble if the CB crits on ME or PK in the opening round, throwing off the entire run. 

Then you have Ma'Shalled who you're not using - he boosts the speed and crit damage of the entire team, plus he puts a leech, which may allow you to lose the lifesteal / have less support champions. 

Lastly, Zavia shouldn't be used on CB, or at least not if you ever auto it, because her A3 will do much less damage than if you just let those poisons tick instead. And even if you only manual it and make sure never to use the A3, isn't it poison overkill with both her and FB? 

I would also suggest you make an unkillable team. It may cost you a lot of silver when switching gears, hitting the right speed, hp, and def, but it is worth it. 

With Frozen Banshee in your team, even without damage from other champions and with only warmaster/giantslayer masteries, you should be able to at least 3 key UNM and 2 key NM. 

Your might also want to build another poisoner and decrease defense champion in case of affinity problems. 

If you can hit the speeds, you should definitely do an unkillable team. 

Maneater, Painkeeper, Frozen Banshee, Septimus, (and Tyrant maybe?) After you get Rhazin you can use him for the 5th slot and you're all set.