A court case isn't the solution to every problem. Sometimes, political disputes need to be worked out by the political process. When two co-equal branches of government have a dispute, the solution isn't to drag in the third branch. If you send everything to court, you don't legalize politics, you just politicize the law.
The political process is messy, but at least it's accountable to the people. If the President angers the people by holding back documents, he will fail to be re-elected (or, if already a lame duck, will become unpopular and have trouble passing his other priorities). If Congress angers the people by asking for too much, they will suffer the same fate (except that they are not, unfortunately, term-limited). In neither case would imposing a judgment from an unelected panel do anything except lessen the people's power.
Congress has all the tools it needs at its disposal. They can make life difficult for the President in many ways, not least of which is impeachment. Short of that, there are all the methods mentioned in the article, methods which are certainly not "overkill." The Congress is the most powerful branch of government. They need only use the power that the Constitution grants them, and no President would dare claim the privilege again.
