They wouldn’t have two votes in parliament if they win a seat as you seem to have misunderstood. They said that whoever of the two was rostered that week would vote on a bill.

reddit.com/Australia is very hostile to the idea but I am partial to it, especially because it makes campaigning feasible when it otherwise might not be.

The main problem I see (which nobody has mentioned) is that politicians develop relationships with each other, even sometimes with opposition members. These relationships are important but the job-sharing thing weakens the chance of rapport.