Not everyone is contracted at the same time so there is some overlap. I'd guess that there are currently more than 25 people with guaranteed contracts but they're trying to drop the number to around 25.
I'd be guessing very roughly that currently you'd have:
Props: Robbo, Alexander, Slipper, Kepu
Hookers: Moore, TPN, S Fainga'a
Locks: Horwill, Simmons (Sharpe last year. I don't think Douglas or Timani played enough games to lock in a top up and Timani is almost certainly going overseas later in the year)
Backrow: Pocock, Hooper, Higginbotham, Dennis, Palu, Samo
Halfback: Genia, Phipps
5/8: Cooper, Beale
Centres: AAC (Adam Ashley-Cooper), McCabe, Barnes, A Fainga'a
Wing: Ioane, Mitchell, JOC (James O'Connor)
FB: all included elsewhere.
That's already 26 players. I might have missed a couple who might have contracts that haven't expired yet. Not positive the Fainga'as are on guaranteed top up contracts.
The faingaas are not on top ups, but folau is - which rounds off the 25 players.
But yeah, of those staying I'd give Gill a top up over:
Kepu/Slipper, Simmons, Dennis and Phipps. There is also an argument for McCabe IMO, but its one thats been done to death.
Then you take into account those who are leaving: Timani, Barnes, Samo, Mitchell?, Palu?, Beale?
Surely there is some space in there somewhere. Furthermore I dont understand why the number of 25 is rigid. Surely someone like Folau could be signed outside the 25 as part of the advertising budget or something considering he had never played super rugby let alone for the wallabies.
How I'd pick my 25 is to pick the best 22 we could put out, deduct those leaving, and then add the 3 next most crucial players. The ARU are obviously taking a punt on the fact that Gill will stick around on less money out of a desire to play for the wallabies. They are then offering the money to the fringe players in order to keep them around. The down side to this is you lose guys who are expected to hang round on the cheap out of pure desire like Timani, Kimlin and Palmer. Whilst not starting wallabies, these blokes still have value to the wallabies and aus rugby.
You can't tell me the loss of Kepu/Slipper, Simmons, Dennis and Phipps, would impact australian rugby in the same way the loss of Gill would. The props you could make an argument for since we are pretty weak in the front row, but in the grand scheme of things they aren't great players and wouldn't make the 30 man in any other top 5 rugby nation.
I realise the above is a little off topic, but I just think it is somewhat dumb to risk losing Gill in order to give Phipps or Simmons or Dennis a contract.