Wellington District Court judge Bruce Davidson today sentenced the youths to two years and four months in jail and ordered them each to pay a total of $980 in reparation to their victims.
He sentenced Williams to nine months of home detention and 220 hours of community service, and ordered him to pay $380 in reparation.
Defence counsel for the younger men argued their remorse, youth, guilty pleas, willingness to pay reparation and participation in restorative justice were mitigating factors.
The men had issues with cannabis use, which was a factor in their offending, and were willing to take part in counselling or had already begun to address the issue.
Williams' lawyer argued he had become involved late in the plans for the first robbery. As the oldest he acknowledged he should have done more to stop the men, but was shy and gentle by nature.
His guilty plea, remorse and cooperation with police were all mitigating factors.
Counsel for all the men argued for home detention but Judge Davidson said there was a need for the sentences to be a consistent deterrent to such crimes.
"It is well known aggravated robberies of small commercial premises are epidemic," he said.
Judge Davidson said the victims had been alone, surprised and vulnerable and had suffered emotional harm.
Although the amounts stolen were relatively small, in the region of several hundred dollars, the robberies also caused damage to the tills and disrupted business.
Judge Davidson said he suspected Williams' role was greater than what was apparent "at first blush".
However, the evidence was mixed and there was nothing to contradict a home detention sentence.