Will a SQL MERGE statement using a parallel(16) hint use more Shared memory than using parallel (8)

Environment:  Oracle EE 12.1.0.2 on Exadata

I'm getting some of the following errors when doing a MERGE using a parallel(16) hint:

ERROR at line 1: ORA-12853: insufficient memory for PX buffers: current 174848K, max needed 1244160K ORA-04031: unable to allocate 32792 bytes of shared memory ("shared pool","unknown object","sga heap(1,0)","PX msg pool")

It was suggested to me to lower the degree to 8.

Will that affect the Shared Pool size and potentially eliminate this error?

The tables in question are not partitioned and the DOP is one (1) on both tables.

Thanks very much!!

-gary