Sure. Those are all equivalent and, depending on the problem, one of them might be easier to apply than the others. All I'm saying is that formal Nodal Analysis is nothing more than the middle one applied systematically.I still say:
You can use these interchangeably:
The sum of currents into a node is zero.
The sum of currents out of a node is zero.
The currents in to a node equals the current out of a node...