In 1993, Cooper was sentenced to six years behind bars for raping a 63-year-old woman.
Mr Mander submitted that the sentencing judge for the more recent convictions failed to address the central issue - whether Cooper was likely to commit another serious offence on his release.
Nor, he said, had sufficient regard been given to protection of the public.
Cooper had denied the offending, shown no remorse and was reluctant to get help for the underlying causes of his behaviour.
In psychologist's, psychiatrist's and pre-sentence reports, he was described as being a high risk of reoffending.
There was no real chance of him voluntarily undertaking effective intervention in the course of his lengthy finite sentence, Mr Mander said.
In October 2009, Cooper left a bar and walked 3km to the property of a woman he knew. He beat her and held a knife to another woman's throat, before driving drunk to a second house, breaking in and raping a teenager.
He undressed, punched the girl repeatedly and threatened to slit her throat and kill her flatmate if she made any noise.
"There is no indication that this prisoner will be willing to enter into any rehabilitation programmes," Mr Mander told Justices Ellen France, Forrest Miller and Raynor Asher in the Court of Appeal.
Cooper's lawyer Tony Snell said at the time of sentencing his client was willing to undergo the sex offender programmes, but that required an admission of guilt and acknowledgement of the offending.
Mr Snell had had no instructions so far that Cooper admitted guilt.
"Unless he does the programmes, this man will not be released, I submit, until he is at least in his 50s," the lawyer said.
He did not think it was unusual for someone to be in denial and some time later have a change of mind.
The Court of Appeal reserved its decision.
