Difficult time! been there, probably the worst you'll ever experience at this phase.
But it gets better I'm so glad to be free also!!
In answer to your questions there is no way she can get 80% she's dreaming, given the equality in family income of both is within 20% of each other.
On the information you have posted the split is most definitely going to be 60/40 to wife.(that scenario would be for a Dad that had the kids part time i.e every second wkend).
If the custody is 50/50 then maybe he can find a more equitable financial cut?
The problem is that everyone gets in her ear and all they advise is to fleece the man for all he's worth in what ever way they think "is there god given right".


My advice
1st get a statutory declaration from the family courts to say they both have formally split(reason because she can continue to divide all asset wealth up until lodged with the family courts),
Then drop her like a sack of potato's accept 65% loss of assets as the worst outcome and settle at that figure he will need to lawyer up if she has already, just get the lawyer to draw up a formal asset settlement doco and custody doco for her to sign and offer it to her lawyer for acceptance.
She will hold out as advised by her lawyer and the lawyer wheels will begin to spin.
At that time sack your lawyer and use the knowledge gained thus far and doco templates that they have already written up to counter with your own settlement figure and try to get her to settle and sign this way and outside of court.
The courts cannot order him to drop his house price.
It is in his best interest to settle out of court and pay her out as quick as possible.
Beware of a thing called spousal maintenance and her trying to take the kids interstate or overseas make sure you put stops on the kids passports etc.
Good friends he will need. Goodluck.