Ambiguity of 4-3-3

Briefly explained in this earlier article, the definition of 4-3-3 is somewhat ambiguous.

Traditionally, it's understood as an evolutionary product of 4-2-4, which roots all the way to WM. Problem is, this strategy is very flexible from the waist up, and for each of its offensive variations there's a different matching defensive concept.

In Rinus Michels' 4-3-3.