How to render multiple objects at one layer?

So, I have zombie object that splits on two objects: body and hand. On scene there are multiple zombies, and sometimes they overlay on each other. And when it happens, hand of one zombie shows on top of another. I thought that sorting layers can help, but I have multiple objects. Aslo I thought that merging textures can help, but it’s too expensive.

Look at the SpriteRenderer in the Inspector, and you’ll see a parameter named Order in Layer:
193864-sorting.jpg

You can also set it programmatically (but take note that it’s actually called rendererPriority in script) so that whenever you instantiate a new zombie sprite, you increment this value (or choose some other way of doing it, up to you).