They need ALL independent senators, not just the Greens. That includes Senator Xenophon, who once was a member of the young Liberals, and Sen. Fielding. So making more appealing to Bob Biege would make it less appealing to the other two.
They would have been criticised if they offered a 'traditional' election budget of handouts and tax cuts, so I can see what they are trying to do.
It seems to have taken the wind out of Joe Hockey's sails. He is all over the shop this morning.