Farhad Qaumi once told a couple of gang associates that the city was theirs if they didn't get locked up and claimed that "if you put fear in the members' hearts they'll obey you".

"The aim of Farhad Qaumi was that the gang would become the biggest or one of the biggest gangs in Sydney," Deputy Senior Crown Prosecutor Ken McKay submitted during Qaumi's sentencing hearing this week.

Now the married 34-year-old spends his days in extreme conditions in Goulburn's Supermax prison, a court has heard, suffering post traumatic stress disorder and facing life behind bars.

The ex-BFL Blacktown chapter leader and his brothers Jamil and Mumtaz Qaumi were convicted over a string of violent crimes carried out during the group's reign in Sydney in 2013.

The crimes included the manslaughter of Mahmoud Hamzy in Revesby Heights, soliciting to murder BFL member Michael Odisho and shooting of a teenage girl.

Farhad and Mumtaz, 31, are also being sentenced for organising the murder of debt collector Joe Antoun at his Strathfield home in December, 2013.

The influence the gang had was detailed in the NSW Supreme Court on Thursday and Friday as the crown submitted Farhad and Mumtaz should be sentenced to life behind bars.

Mr McKay said the criminal gang believed it could become the most feared group in Sydney.

"The aim of the group was to make money from criminal acts including the use of violence and threat of violence," he stated in his written submissions.

However, Farhad's barrister John Stratton SC said the suggestion Qaumi wanted to take over Sydney was not supported by evidence.

If that was his motivation in wanting to shoot rival Mahmoud Hamzy in October 2013, the jury would have convicted him of murder rather than the lesser charge of manslaughter, Mr Stratton said.

The shooting of Mahmoud Hamzy in the garage of his family's Revesby Heights home marked a turning point in the relationship between the Bankstown and Blacktown BFL chapters.

Months prior, Farhad Qaumi made an agreement with Bankstown chapter leader Mohammed Hamzy that he would control the Blacktown chapter, with territory stretching from Granville to Penrith, Mr McKay submitted.

Tensions were sparked when someone later told Qaumi that Mohammed Hamzy - nicknamed "little crazy" or LC - wanted to kill him.

Jamil Qaumi and two others went to Revesby Heights with guns while Farhad and Mumtaz went to a pub in the city in their pursuit of an alibi.

However Mohammed Hamzy managed to jump out of the line of fire while his cousin, Mahmoud Hamzy, was killed and friend, Omar Ajaj, was shot in the leg and stomach.

Mr McKay submitted that the Qaumis believed Hamzy was capable of killing and saw profit in removing him from the picture.

"The aim was to kill not warn," he stated.

However both defence for Farhad and Jamil, 24, said there was evidence of a contract out on Farhad's life before the shooting, giving rise to aspects of self-defence.

Days later, Abdul Abu-Mahmoud was shot sitting in his car outside the Chokolatta Cafe in Bankstown because the Blacktown BFL believed he could pass on their addresses to their enemies.

Mumtaz and Jamil were convicted with shoot with intent to murder and solicit to murder over that shooting.

Jamil's barrister Nicole Carroll said for a significant part of Jamil's life he was very close to his brother.

"That is something that undoubtedly, consciously or unconsciously, would have come into play in terms of his level of commitment to doing what his older brother asked of him," she told the court on Friday.

Ms Carroll said the brothers had different levels of criminality and they should not be treated together because they were siblings.

Farhad and Mumtaz Qaumi were also found guilty of a drive-by shooting at Greenacre, targeting a home on November 29, 2013.

The sentencing hearing has been adjourned to April 26.

First appeared on the SMH