At light weight . Definitely old v new school here . Modern day rules but at 40 Rounds . Who walks out the winner ?
Depends on if Nelson can get to the longer distance. He had massive trouble with Wolgast. And Shane was a huge, physical puncher. My gut feeling is Shane. So I pick him.
My personal pick is Shane ,if it was a shorter distance such as 12 or 15 but over the longer haul Nelson wears him down . But as you said ,it really depends on BN getting through . But I believe he was only stopped once ?so that could be a factor .
Bat Nelson would outlast him and wear him down. You are not beating Bat over 40 rounds, unless you can last that sort of distance!