That's another thing in Madden that's a major misconception.
Will = Weak side linebacker
Sam = Strong side linebacker
Mike = Middle linebacker
The Will may be your ROLB on one play, and the LOLB on the next, depending of the personell packaging your opponent uses. In the NFL, teams have designated Will, Mike, and Sam backers. For instance, Lance Briggs on Chicago will always play the Will position, aligning himself on the backside of the formation. But in Madden, it's nearly impossible to replicate.