Lads, what planet are you on?
Keane was a hard footballer but in comparison to, for instance, Sonny Bill Williams, who has boxed at heavyweight professionally. He would get killed. That's just in a boxing match. In an actual tear up I'd pick and rugby player over any footballer. I'm saying this because I've played rugby at county level and football for uni. I went to school with and am good friends with a raft of rugby players including Richard Wigglesworth and the Sanderson brothers all of who played for England. Wiggy was the smallest rugby player I've ever played with at a decent level but was much more of an athletic package than any footballer I've ever played with.
I get it that you love footy and so do I but there's no comparison between the athletic packages of a rugby player and a footballer and obviously you get the whole range of body types in rugby from props through flankers, centres and wing.