Can you work for 12 months for 2 different employers on a WHV? Been on DIAC website but cant really find any info all it says is work upto 6 months with each employer to me that suggests you would be able to work for someone else aswell? Cant seem to find an email adress to contact DIAC direct either?

In 365 days you can work for 365 employers if that's what floats your boat. You simply cannot work for any single employer for more than 6 months total.

^ what she said. I remember reading it in some of the DIAC guidelines that they did not treat overtime in lieu of the calendar time necessary to make up to a requrement - e.g. pulling 80-hour weeks for 6 months would not gain you an equivalent of 12 months work experience as it were. Applying same logic to working for two employers concurrently (I think this is what you think of doing) - IMO the immigration would look at the actual calendar time worked for any particular business, so as long as it is 6 months with one and 6 months with the other one, you are ok. 12 months half-time in one place would not work me thinks.