Cousins can't guard the four. He'd get killed against stretch 4s, probably foul out in the first half or sit 80% of the game on the sidelines. Until the Kings can prove they can get Cousins the ball in the right place down low on a regular basis I think the stretch 4 fouls him out much sooner than the other way around. Also, it's a lot easier to double Cousins down low than a 4 on the wing. Heck, Cousins has a hard time staying in the game playing against centers, much less stretch 4s. The only way it works is if the guy you play at center can guard the stretch 4, and that seems to be a rare commodity.
By the way, if Malone is going to demand much more defense from Cousins, it is going to be interesting to see if Cousins is going to be able to keep from compiling fouls at a fantastic rate while playing such defense. There could be a fairly long learning curve in which Cousins gets used to playing high effort D like Malone wants while simultaneously learning how to do it with not fouling out. IMO, part of the reason behind the Cousins' "laziness" on D last year was his frustration with accumulating fouls at a high rate. He might have thought it's just easier to stay in the game if he doesn't play D altogether. And speaking of frustration, we all know that's the source of his acting out. If high defensive effort leads to more fouls, which leads to more frustration, that could be Cousins' main challenge early in the season.