Agreed. Fixing a system with incomplete understanding of a second one is unlikely to be useful. If he's just thinking of combining (in himself) two disparate arts to get the strengths of both, that's a different matter.It depends on what it is you are trying to mix, and what you are trying to accomplish by doing so. "Fixing" one system by mixing in fundamental principles from another system is not likely to work well. That is the impression I got from the OP, in what he is thinking of.