I dont see Good and Evil as how you go about solving a problem, I see it as how selfish you are, and how willing you are to exploit and demise innocent life for personal gain/goal. Someone who is violent and merciless and never forgives but at the same time is fighting for the people and likes to smite evil and make them feel pain is still Good. They may be Brutal Good, but they just gain pleasure out of making the "Evil" feel pain by avenging the pain they caused to innocent people. This is why a third alignment axis should be added, one that encompasses the level of violence, forgiveness, and regret. Such as Passive/Moderate/Brutal.
Here is examples of this third axis I thought of as applied to Chaotic Good.
For example, batman is Passive Chaotic Good, because he clearly goes against the law and lives by his own system inorder to punish and go after criminals, however he is not willing to crossover the line and commit true violence and if he ever had to kill someone, he would deeply regret his descisions and such. Passive characters believe more in reform and may forgive.
A Moderate Chaotic good character would be your standard vigilante who goes after the badguys, shoots them, and thats about it. They arent out neccessarily to make them suffer or completely avenge the pain of their victims, but they want them to be dead and out of this world.
A Brutal chaotic good character would go after the badguys, slaughter them, kill them, make them feel pain inorder to avenge the people in which they hurt. They feel pleasure in killing badguys, and have a bloodlust about them because afterall, these dirtbags who harm innocents need to feel immense pain and suffering. However, they are still good because they are always here to protect the innocent, and never will let their bloodlust harm an innocent bystander, only the truly bad perpatrator, heck, Brutal good characters would even host fundraisers and other things for the common good of society. Brutal Chaotic Good would still not let ANY innocent person be harmed at all ever, but basically go all out on the badguys.
Basically what I am trying to say is, Evil would be independent from Brutality, because Evil implies personal gain, self exploition, and other things, while Brutality implies the means in which you achieve things. A Brutal Chaotic Evil character may desire to slaughter little children, but a Brutal Chaotic Good character would find this sick bastard and shove his face into spikes as punishment.
A Brutal Lawful Good Paladin may have a bloodlust to go out and slay the dragons and demons and other crime infesting their city, while a Passive Lawful Good character would be that typical superhero who always lets the badguys get away and thinks they are reformed, like that guilable goody goody.