The 32-year-old will have his first parole board hearing in December after being jailed yesterday for five years.
He must serve one third of that, but has already been behind bars for 17 months so will be eligible for his first parole hearing in little more than three months.
Garth McVicar, of the Sensible Sentencing Trust, last night said the sentence sent "all the wrong messages".
"We believe if there was ever a case for consecutive sentences this was it." The arson charges alone could have kept Macdonald behind bars longer, he said.
He also did not believe Macdonald should have got any discount for his guilty plea.
"He waited until the last minute [to confess] until he was nailed by [Callum] Boe and the evidence was overwhelming."
Board spokeswoman Sonja de Friez said 90% of all offenders were declined parole at their first hearing date, which was generally an opportunity to assess an offender in terms of what rehabilitation they needed in prison.
And, although Macdonald was eligible for parole, the board might never see fit to grant him an early release, meaning he would serve his full sentence, she said.
At his sentencing yesterday it emerged Macdonald had written a letter to apologise for the hurt and fear he caused his victims, but that failed to convince a judge, who said he had "seen and heard no sign of remorse".
Macdonald wrote that he was ashamed, and hoped it would be looked upon favourably.
It was not.
Justice Simon France told the sentencing hearing in the High Court at Palmerston North he had the benefit of seeing Macdonald's admissions during his videotaped interviews with police.
They were made while he was being investigated for his brother-in-law Scott Guy's murder - a charge he was arrested and then acquitted for at a trial this year.
He confessed to six crimes and was jailed for a total of five years for them yesterday.
Justice France said those admissions came after the weight of evidence became apparent and he "saw and heard no remorse".
"I have had regard to your initial denials, and the manner of them, and then also to your subsequent admissions to this offending, and the manner of them. I saw and heard no sign of remorse; indeed if anything the statements were consistent with continuing indifference."
Crown prosecutor Paul Murray said the offending, except the deer poaching, was motivated by "vengeance".
Mr Murray said Macdonald told a probation officer the retribution against farmer Paul Barber was justified.
"Each offence derives from a sense of entitlement and one that still seems to exist now," he said.
In that case - furious that he had been caught poaching - he killed 19 calves with a hammer blow to the head, after he emptied thousands of dollars of milk from a vat from Mr Barber's neighbour, Graeme Sexton.
"Rather than being deterred, you decided on a much more callous and brutal revenge," the judge said.
Mr Sexton felt the wrath of Macdonald and his accomplice, Callum Boe, because Macdonald believed he had told people about the poaching of stags over many years, when he fired shots close to Mr Sexton's home that unsettled Mr Sexton's family.
A year later he returned to the Sexton farm and burned down a "treasured" old whare, a crime the family believed was done because he knew it would hurt them.
But it was the crimes against Scott and Kylee Guy that were "personal and done with the intention to unsettle", the court heard.
In those attacks he burned an old home down that was waiting to be moved from the Guys' property and wrote "horrible insults" on the walls of the couple's near-new home, which was also extensively vandalised.
"The impact on them and the wider family, including your own, was significant ... The offending impacted significantly on Mr and Mrs Guy, as one would expect, but the impact went wider than that and impacted all your wider family."
Especially hurt were his former parents-in-law, Bryan and Jo Guy, who "provided you with so much".
When he walked into court Macdonald smiled at his legal team and mouthed the words "good morning" to them, then looked quickly to the public gallery where his parents, Kerry and Marlene, were seated.
On Macdonald's behalf, Greg King said the comment regarding Mr Barber was made at the time and was not Macdonald's position now.
He argued Macdonald had shown remorse and pointed to his wife Anna's evidence at trial, where she told of a changed man who was making an effort to get along with Scott and Kylee.
"These were all the actions of a person who realised that idiot he'd become. He regretted intensely the person he'd become," Mr King said.
The sentences
• Theft of stag: 9 months' jail
• Intentional damage (milk vat): 9 months
• Intentional damage (killing calves): 1 year
• Arson (burning the whare): 2 years
AGAINST SCOTT AND KYLEE GUY:
• Arson: 3 years
• Vandalism and graffiti: 2 years
Total cumulative sentence: 5 years
Eligible for parole: December 2012
