I'm not sure exactly what you're asking or what you mean by "built into an agreement between clubs" but Theo is still under contract with the Red Sox. Yes, there is a multitude of reasons why they don't have much leverage in this matter, but in terms of their ability to demand compensation, he is under contract with them and they decide whether he can go or not. For him to come here, they (technically) have to let him go. Right, but even if Epstein breaches his contract, the Red Sox are only entitled to money (which the Cubs could easily pay), unless there's some sort of MLB contract where teams have agreed to exchange players instead of money in situations like this. Outside of this, I'm sure there's a non-compete in place that would prevent Theo from going to work for another organization. The penalties for that, I'm sure, would have to be determined in a court and I'd bet the Sox would be well within their rights to ask for players as compensation. Then there's the whole tampering thing if the Cubs hire him without the Sox releasing him and the potential penalties from MLB if that happened. This negotiation is by far the quickest and most simple route to go.