Explaining (sorry for my bad English translation)
"Rendering" of sprites / tiles isometrically is a little more complicated than the process explained. The "explained" serves as a working basis and for scenarios where "no sprite" is above / below another (the sprites are just front or back at the same level). In this case the algorithm is clear: follow the drawing order +(Z-X).
But what happens when I have floating elements to a level/height Y?
a-) If the sprites are placed on top of other sprites exactly without overlapping/intersecting with any of them (on the Y axis), the order can be used paint +(Z-X)-Y.
b-) If the sprite "intersects/overlaps" more then 1 sprite simultaneously (in X, Y and/or Z) WE HAVE A PROBLEM: In what order will draw them?. Then we need a complex sorting algorithm to determinate the order. Not to mention when we have "a lot of" floating sprites to be "integrated".
I, after a long analysis (and much suffering), was able to implement an algorithm. I would never have imagine complexity (honestly I thought it will be easier) of this "affair" and I went
finding as I started developing my first game in cocos2d-x 2.5D. An algorithm of this type requires, in the first instance, a "comparison "everything with everything" but is possible to make a lot of optimizations for reducing calculation process so much.
An example (demo) of the algorithm result can be seen here: