The first misunderstanding is why it is a “mask”? It is because other software calls it “clippingmask”. I actually don’t like this name very much.
In krita, it may be called “inherit alpha (one layer)”, so its behavior should not be consistent with “mask”, but should be consistent with “inherit alpha”
Regarding the order, normally it should be from top to bottom, but according to your method…
In addition, there are also issues such as nesting and using to layer groups