Lorne isnt a champion, come on now, we cant just be throwing the word 'champion' around like that.
There were only a few real champions on the show(s), and as much as Lorne is the best character on Ats, he aint a champion.
I think this Champion identification was created specifically for Angel to give him an anchor point for his self-identification and support for his taking on his "redemption path." As such, the title/description is not the same application for the other characters. Lorne, Cordelia, Gunn, Wesley, Fred they all fought against the Doers of Evil and Forces of the Dark. I prefer the id of Heroic Warriors in the Angelverse - the "champion" id to me is one that is connected with the titled being bestowed, in this series, by a supernatural life force or beings.
The other character that I would use "champion" for would be Buffy and the Chosen Ones. As for Angel, I think a lot of the "champion" identification is something that he very much needed to make his life easier to accept with his history as Angelus.
Lorne is most certainly in my category of heroic warriors - and more importantly for me he is a metaphor/symbol of the inherent goodness and development of life - he rejected the brutality of his natural culture and world to instead follow his life that wanted and needed an alternative to the violence, killings and subjugation of classes to create a slave class.
It's an important connection that Lorne rejects any further association with Angel after he is given the duty to kill Lindsey - to me it is Lorne being forced into going against his free will choice not to embrace violence as a part of his life. How much Lorne in AtF directly reflects what Joss Whedon had planned for his LA in Hell - wish there had been more information on how closely the comic book season matched the original TV series plans.
Lorne actually became my favorite character of the Angel series along with Wesley - I don't include Spike because he was firmly established in the Buffy series and came over only for the last TV season.