Can you do it?
Yes, provided the power supply has good voltage regulation and will not go above 5.25V at the low load levels the Pi Zero will use.
When a power supply is rated for 5V and 4A it means it can output 5V at up to 4A. It won't always output 4A, regardless. It will only output what the device needs, and in the case of the Pi Zero that will usually be well under 1A (so there is no advantage in using a 4A PSU on a Pi0).
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?