Sherk is a baby Hughes, anything less than Hughes can't beat BJ, simple as that.
1 BJ has the standup advantage
2 BJJ Advantage
3 Possibly even rivaling Sherk in stregth simply because Hughes is bigger and stronger than Sherk and BJ manhandles him for as long as he wants until he decides to let Hughes win.
The only way Sherk can win is by controling BJ on the ground, who wants to be on the ground with BJ?