Nope, this doesn’t work.
Yes, if you reorder the edit layers, then whatever is at the top, will have the full weight. But painting on it doesn’t erase anything from it’s bottom layers.
You can see this by reordering again.
If you for example make a grass layer, then a rock layer, then a dirt layer, in that order.
You paint rock selecting it’s edit layer (2nd in order). It works.
You then select dirt layer (3rd in order, so the top layer), and paint dirt in the same place. It works.
Now try reordering them again, making rock a higher layer. You will see that the place where you had previously painted rock, still has that rock, so it wasn’t erased.
Or instead of reordering, you can just erase your dirt (holding shift). There will still be rock underneath.
If like you said, selecting the correct edit layer erased layers underneath, then the rock should have been erased.
The way it works right now - is dumb. If we wanted this kind of behavior, we previously had the option of alpha layers which did exactly this. Normal weight blended layers shouldn’t behave this way. It makes the workflow hard, complicated, tedious.
And probably affects performance too, because now in the same place you might have 5 layers painted, when you only need the top one to be visible.