Your Radar looks an awful lot like my Irwin!
That's funny, because Radar's behaviour is a lot like Irwin! Frantic scent marking (he would even rub his side against a wall) and aggresive dominance. He would puff up his fur and sidle and try to mount the other rats, even after a month of attempted intros. If a rat came up behind him, he'd squeak, and the other rats didn't like him. I had him neutered, and even after another couple months I had to put them in a room together with no cage or personal belongings. (that's the only way they wouldn't fight) I let them all live together in this completely un-scented, fresh room for almost a month with a couch to sleep and climb on. Then I finally set up their big cage again with toys and hammocks and stuff and they all climbed in there together. And now they all live peacefully together. Whew!