I went through an additional workflow where I merged the 10 sub-zones together, clipped them to the city limits (original fc) and then ran the SYMMETRICAL DIFFERENCE.
After running the SYMMETRICAL DIFFERENCE I RESHAPED by snapping to and TRACING along the city limits.
Once the symmetrical differences were taken care of, the was a difference of less than 1sq.ft.
Finally to check my work I performed to additional steps by performing a SPATIAL JOINE and Copy Paste Special with FC with 10 polygons to the the MERGED polygon made up of the 10 sub-zones, which concluded in giving me the relatively same difference.