I thought Wing chun was designed to break the structure of the opponent upon contact? If you have perfected that principle then Emin should destroy him as soon as he feels that contact. That being said, if he can control the beast keep him off balance there is your chance. Lesnar is going to swing wildly then go for the shoot. Couture will almost certainly prove the theory that if you can get close, defend the takedown brock can be easily stopped Lesnar's JJ is subpar at best he will just never be flexible enough (with all that muscle) to really roll with the top guys in the game. Frank Mir showed that technique can overcome strength. Mir used JJ Emin will use WC IMO the outcome will be the same.
"Blessed be the LORD my strength which teacheth my hands to war, and my fingers to fight."-Psalms 144:1
"I Am The Punishment Of God, If You Had Not Committed Great Sins, God Would Not Have Sent A Punishment Like Me Upon You"-Genghis Khan
"The light of the eyes is a comet, And ones' activity is as lightning, The sword that kills the man; is the sword that saves the man"