After being chased through the streets of a country town, Nicholas Henry jumped out of his van and tried to run away.

But the 18-year-old never stood a chance.

The three men, who had forced his van off the road to hunt him down, bashed Mr Henry after he fell to the ground.

As he lay there, defenceless and alone, the group took out a knife and stabbed him to death in Morwell in Victoria's Gippsland region in February 2021.

Brothers Corey and Brayden Smart and friend Abraham Abas, who all pleaded guilty to manslaughter, learnt their fate at the Supreme Court in Melbourne on Thursday.

Prosecutors could not establish who out of the three men wielded the knife, but they all pleaded on the basis of complicity.

Nicholas Henry was 18 when he was stabbed to death by three men in Morwell

Corey Smart (second right) was sentenced to eight-and-a-half years on Thursday. The judge told the court Corey played the most 'significant role in the offending'

The group's attack was 'haphazard and chaotic' lasting less than a minute, Justice Jane Dixon said.

'It was clear that Nicholas Henry was deeply loved by family and friends,' she said.

'The grievous loss of a young man's life ... is a terrible thing.'

The group were motivated by revenge, believing Mr Henry had broken into Corey's girlfriend's car earlier, outside an RSL, on February 20, 2021.

Corey Smart gathered his brother and Abas and drove them to hunt for Mr Henry, who was living in his van, finding him and then following him through Morwell.

He forced Mr Henry's van off the road, it mounted a gutter and crashed into a fence on Buckley Street.

Mr Henry got out and tried to flee but the three men chased after him and began assaulting him when he fell to the ground.

'You dog, you rat,' a neighbour heard one of the three offenders yell.

Brothers Brayden and Corey Smart, and Abraham Abas were sentenced on Thursday

They stabbed him eight times across his back, thigh and bottom, leaving him bleeding profusely.

He was taken to hospital, where he died a few hours later.

Justice Dixon found the three killers had suffered from difficult childhoods, including Abas whose mother had fled with him from Sudan after his father and grandmother were killed by rebels.

She said their rehabilitation prospects were good and their guilty pleas 'very valuable' as they had avoided a four-week trial.

Nicholas Henry was chased down across Morwell in Victoria's southeast in February 2021, before being cornered and surrounding by three men who stabbed him eight times

She jailed Corey Smart for eight years and six months, as he had played the most 'significant role in the offending'.

His brother and Abas were each handed seven-and-a-half year sentences.

Corey Smart will be eligible for parole after serving five years, while his brother and Abas can apply after four years and six months.

They have each already served more than two years and four months.

The three men smiled and embraced each other after hearing their sentences, with supporters telling them 'see you soon' and 'love youse boys' outside the court room as they were escorted by custody officers.