I was wondering exactly the same thing why we need to un-screw the screen? Anyway place the screws in the order they come and you should find no problems putting them back in right order.
Also I found the screw driver comes with ifixit battery kit does not fit in the screws perfectly. Feeling a little large for these screws. Anyone else had the same experience?
You may need to use tweezers to carefully bend the metal bracket to make it fit tightly into the slots over the home button connector