WCS just spent a year as a PF next to a poor man's Cousins.
IF you watch games of Kentucky of this past season, you notice, that all the good teams just put their PF on WCS with the game plan of never losing contact with him, when he was closer than 15 feet to the hoop. Forcing defender to stay at home - that's kinda the main attraction of stretch 4s.
Some opponents did leave WCS, when he drifted to perimeter, crowding paint and giving him 4-6 feet, because Kentucky used WCS as a guy swinging the ball at the top of the arc (Calipari is great at recruiting and mental preparation, average at game time), but never ran screen action either for a shooter to receive the ball off a curl (Mclemore scored .94 PPP off screens last year - 12th last year among guys with at least 100 possessions, Nik had .97 PPP in 39 possessions; average half court possession yields .89 PPP) or a ballhandler to shoot (Darren Collison was tied at #6-#8 in the league scoring as a ballhandler after screen action with at least 100 possessions at .94 PPP). Notice, that was usually with a big defender nearby and Kings bigs not being devastating roll options, plus includes Corbin era. It's just two simple plays off the top of my head - I believe, Karl might think of something more sophisticated.
P.S. From Mr Jones:
http://www.sacbee.com/sports/nba/sacramento-kings/kings-blog/article21142326.html
P.S. 2. Larry is blowing smoke:
http://basketball.realgm.com/wiretap/237815/Larry-Bird-Believes-Willie-Cauley-Stein-Is-A-$100M-Player