Does `a "group" option and adding a "group" option' a meaningless repeatition?

[Regid Ichira]

Quoting /usr/share/doc/exim4-base/README.Debian.gz :

    If any of your aliases expand to pipes or files or directories you
   should set up a user and a group for these deliveries to run under. You
   can do this by setting the "user" and - if necessary - a "group" option
   and adding a "group" option if necessary. Alternatively, you can
   specify "user" and/or "group" on the transports that are used.

I am confused by 

  You can do this by setting the "user" and - if necessary - a "group" option
  and adding a "group" option if necessary. 

Isn't it repeating twice, in a sequence and in the same sentence, the 
suggestion of adding a "group" option to the router?