netgroup/nfs question

If I have a netgroup like this:

dcs-systems dcs-users dcssys

dcs-users (,username,)

dcssys \
(hostname,,)

....and then an NFS export like:

/path/to/mail @dcs-systems(rw,sync)

Am I recalling correctly that it's a known problem that the export will
end up being read/write to hostname, but read only to everything else?

Thanks!