I currently have small whirlwind malina, golden nettle, bucaneer rosa and livonah as my 4 plus an assist as my front line. I was thinking of taking out livonah becasue of her minus 2 cannons and pluging some1 else in. I can either have dark ruby 8830 atk or firebal reesa with 7300 atk. Im leaning towards reesa beacsue shell have 4 extra cannons from netttle and maline plus she has her skill that could activate. Any ideas?

I'd personally go for Reesa, simply because she will allow for Bellator Combos and Ruby won't.

Also, keep in mind cannons get distributed equally. So the more Pirates you have that get affected by a cannon Skill, the lesser their ATK Boost will be. Also, Reesa activates before cannons, so sadly, she won't increase the cannons damage boost.

With malina and nettle they give bellator cards +2 cannons. doesnt that mean +2 cannons each? if not woudnt it be better to have less bellator so they get max coverfire

Having more or less Pirates that get affected won't change a single thing about the total Damage Output. And the total Damage Output is what affects Brawl Point gain. However, the fact that Reesa can Combo with your other Pirates, means that your total Damage Output is higher with Reesa than with Dark Squire Ruby.

But if you want a focussed offense (targetting specific Pirates in your opponents Defense), then you could consider Ruby to make Malina and Nettle stronger.

But also keep in mind that if Reesa's Skill activates, she has more Attack than Ruby, which will increase your total Damage Output even more (and with it, your Brawl Points).