Speaking of backstory to the game...
I live in the USA, and so thus Cartoon Network shows a good bit of dubbed anime.
Gundam Wing features 5 teenage boys who pilot super-powered mechs and fight mobile dolls.
The thing is, it's not likely that you'd see Duo with the Deathscythe just duking it out with Heero. They're friends, they both work for Doctor J, they probably wouldn't just have a big gang bang.
That's sort of beside the point though, since what fun would Endless Duel be if you could only match the Gundams up against the Oz mobile suits, which don't even have human pilots?