Here is my suggestion to fix this ludicrous aspect of the American way.
Pretty numptyish solutions to the problem.
1) "person in that knowledge field" is an even more difficult term than the "reasonable person" making an obvious discovery. If you look at the history of patents most abuse has come from large companies with more resources than patent holders. What you suggest would further entrench this system.
2) don't encourage even more litigation. In such an unlikely situation then the government should simply license the relevant patents.
The problems with the US patent system are well known: patents in too many fields are granted too readily and the courts, notably the one in east Texas then get to deliberate on their validity.
The US patent system must be overhauled so that it is sufficiently resourced to check patents. In the case of some of the vaguer software and business patents, which are the ones that cause most of the problems, applicants could be required to demonstrate specific applications. Because it is often the blanket application of a relatively minor patent across a whole field that causes problems. Cf. this one and the website plugin one. The patent clerks should have the authority to reject these applications on sight – though applicants should also have the right to appeal.