Yeah Rashad gets tagged and Anderson is an elite striker. Silva gets taken down and Rashad is an elite wrestler.
I'm not saying that Rashad goes in there and is just going to rag doll Silva and win for sure. But history has shown that Silva has a problem with good wrestlers and that is exactly what Rashad is.
Anderson's wrestling defence is his weak point, but it's also something that he's improved on as was demonstrated in the 2nd round of his rematch against Sonnen. Is it good enough to stop Rashad every time? Of course not. But it's good enough to give him plenty of chances to knock Rashad's head off over the course of a 5 round fight.
Also, Rashad is NOT an elite wrestler. Good, but not elite. Elite is GSP level when you can take anyone down any time with seemingly little effort. Rashad ain't that good, and furthermore as I pointed out earlier, his top control and ability to do damage is lacking.