We need to encourage the client to make the site unique in terms of content. This is to avoid 2 possible penalties.
Content duplication concern with workingholiday.com website.
Doorway penalty since many pages were linking/pointing to another website owned by client.
If the site get the penalty it will become harmful than helpful.
It has been spammers strategy in online marketing to create multiple websites pointing traffic to the main website through links. Due to same IP and same content, it will be very obvious to Google spam team.