The code I used for my game is like this:

import math,pygame
class Square(object):
    def __init__(self, image, gridpos,level=0):
        self.image=image
        self.gridpos=gridpos
        self.isopos=[int(i*16) for i in gridpos]
        self.recalculateRealpos()
        
        self.level=level
    def draw(self, surface):
        pos=(self.realpos[0]+self.offset[0]+surface.get_width()/2,
             self.realpos[1]+self.offset[1])
        surface.blit(self.image,pos)
    def update(self,*args): pass
    def recalculateRealpos(self):
        self.realpos=(int((self.isopos[0]-self.isopos[1])*2),
                      int((self.isopos[0]+self.isopos[1])))
        self.offset=(-self.image.get_width()/2,-self.image.get_height()-2*self.isopos[2]+48)
    def __gt__(self, other):
        if math.ceil(self.realpos[1]/16.0)!=math.ceil(other.realpos[1]/16.0):
            return self.realpos[1]>other.realpos[1]
        else:
            return self.level>other.level
    def __lt__(self, other):
        if math.ceil(self.realpos[1]/16.0)!=math.ceil(other.realpos[1]/16.0):
            return self.realpos[1]<other.realpos[1]
        else:
            return self.level<other.level

All you need to do is sort your list of objects and it looks fine. The system also supports relative scrolling, though it got to slow for me with larger rooms. Note that my tile size here was 64*64 and you might need to switch up the numbers if you have different sizes or angles. You can download the source for my game if you want to see how it is used (see my signature)

I am not sure if this is what you are looking for, but I hope it helps.