My DH took his long service leave at half pay when DD was 11 months old (not quite the same as 6 months) and it was the most wonderful thing for them. He had 6 months at home with her. They are so close now and it meant she was 18 months when she went to day care. We felt lucky to have had her home with us for all that time. I missed her terribly and thought I'd miss out on things but it I jsut had to remind misyelf DH had missed out on so much already!
If it ends up that he can't take it and you get your work scheme and the government scheme at the same time (in my job I will get both) maybe you could save the 18 weeks worth of money for him to stay home later on?