File Under: Negotiate, Negotiate, Negotiate
When we send over our initial contracts, we include things that are both enforceable and unenforceable (with respect to Major League Baseball's Collective Bargaining Agreement). Not all agents catch them, but the good ones do and point out the unenforceable portions out and tell us to remove those provisions. We then talk privately and say, yea he's right, and we then remove the provision.
As every lawyer will tell you, everything's negotiable. So, when you get that "take it or leave it contract" for the first time, read it and negotiate! If the other party is not willing to negotiate, then you may just have to walk away from the deal.