I'm a great admirer of both your own and Richard Rumult's work and use elements of both in my own teaching and practice. The main difference I see between Playing to Win and The Crux is the narrower focus of the latter, as described in the last two chapters of the book about the 'Strategy 'Foundry'. This apprpach takes startegy focus and action to an extreme by defining strategy as the solution to one high priority problem. Strategy changes as frequently as the priority prolem changes. I find this too reductive an appropach to strategy: too many relevant considerations are left out in pursuit of the singular problem focus. By contrast, WTPHTW model allows more visibilty of the full scope and logic of strategy, from market to position to capability to system, around which multiple problems can be defined at a lower order. In that way both approaches can work together. Hope that's helpful.