How are Legion savages?
From what I can see they are well dressed, well mannered, and have fairly good discipline and structure.
Please explain to me how they are savages.

Are yous serious? lol well dressed plzzzzz. I dont think having skirts all the time that look like they came out of dumpster can be considered well dressed. Plus well mannered??? what kind of manners do they possibly have they constantly insult people if there not them. I think thats kinda rude...They may have some good discipline but its not the right kind.

It's highly possible, however I think it would be tough to convince him at first, the man would likely think you're attempting to manipulate him, though a show of good faith regarding his securitron army would probably alleviate that fear my main concern would be the changes with the Legion itself.
I think there might be difficulty with them accepting such a radical overhaul, though perhaps I underestimate their devotion to the Caesar.

The Legion have excellent discipline, once they see you as an equal they're very polite and well dressed is a matter of perspective, they're better dressed than most wastelanders but I think while NCR uniforms are generally untidy they do look better.
Of course, we can argue that their kindness when they see you do well strongly infers their group mentality defines their kindness, so it's up to how you define well mannered...The White Gloves strive to be well mannered...

It annoys me that cannon fodd... sorry, recruit legionaries talk down to completely random people. If they were criminals or NCR citizens, sure, but otherwise, its just some extremely lowly soldier insulting you for no reason.

Well it's their culture I guess.
Since you're not part of it and know little to nothing about it they talk down to you because of it.
Wouldn't say they're bad mannered or anything, just part of their culture.
Just like how certain brute races in science fiction values honor and respect and battle prowess and talks down to those who believes in something else.
Sure it's very single minded but aren't most people who believe in something greater that way?

I agree but, being a female with the Black Widow perk, I can just go around having six with anybody..... especially in the Strip :hubbahubba:

Put Melody (the slave girl) in charge immediately after I gain power.

Then recruit the Remnants to wipe out the Legions camp all on there own.