Folks reinventing it
Intensifying and Elaborating the Core Concept of a Multi-factorial Array for Wandering Monster Generation
The core of the idea is to extend the single-factor wandering monster table into a multi-factorial one (the original single factor is "monster type" to which I simply added an ontological extension covering the kind of presence the monster has in the encounter). One could extend this process in various ways so long as one continued to generate interesting properties to serve as the basis of additional axes, and was able to track it effectively. Because of the limitations of paper as a surface for representations, this is difficult to extend past two factors, but a simple computer program could be written to include things like factional allegiance or preparedness/surprise. So long as the program generated a value in a multi-dimensional array rather than simply treating each as an independent factor, you would be able to produce interesting, meaningful and surprising results rapidly. I have no time or especial interest in generating such an array, but others might find it interesting as an exercise and I would encourage you to share your results.