What is the benefit of using Workgroup ?

We are using Novell as NOS and there are a number of remote sites with
different subnet linked with high speed link. At the present moment, the
whole organization uses the same Workgroup name.

However, a consultant suggests us to use different workgroup name in
different site. For instance, in Site A, he suggests using AreaA while in
Site B uses SiteB as workgroup name.

I would like to know what is the benefit of doing so ?