Shared Volumes Question

If I have

version: "3.8"

services: 
  example1:
    image: example.com/example1:latest
  ports: 8000:80
volumes: 
  - shared_example:/data
services: 
  example2:
    image: example.com/example2:latest
  ports: 8080:80
volumes: 
  - shared_example:/data

volumes:
  shared_example: 
    driver_opts: 
      type: nfs
      o: "192.100.1.100, nolock,soft,rw"
      device: ":/local/shared"

Will that slow things down or is the proper solution to have

volumes:
  shared_example1: 
    driver_opts: 
      type: nfs
      o: "192.100.1.100, nolock,soft,rw"
      device: ":/local/shared"
  shared_example2: 
    driver_opts: 
      type: nfs
      o: "192.100.1.100, nolock,soft,rw"
      device: ":/local/shared"

Or even

volumes:
  shared_example1:
  shared_example2: 
    driver_opts: 
    type: nfs
      o: "192.100.1.100, nolock,soft,rw"
      device: ":/local/shared"