McCarthy was a major participant in the ring, which was broken when police made their arrests, Justice Gendall said. He set up and tended 10 cannabis plots, helped with the harvesting - assisted by armed men wearing balaclavas - and sold cannabis in bulk.
The total number of cannabis plants grown during the time police were following the ring was unknown, he said, but 361 plants were found in seven plots.
Defence lawyer John Westgate said McCarthy had been "seduced by the lifestyle of selling cannabis" and would "regret it forever".
McCarthy had lost a huge amount personally because of his offending, including having $111,000 in a trust account and his $580,000 home seized by the Crown, Mr Westgate said.
Sonia Vidal, defence lawyer for Anderson, said it was accepted he was a "foot soldier" in the cannabis ring "whereas McCarthy was at the top".
Anderson told police last year he had agreed to sell drugs because he was in debt and selling seemed like an easy way out.
Justice Gendall said monitoring of Anderson's cellphone showed he offered to sell cannabis 42 times between June 2011 and April last year. He also helped to harvest 62 plants during the 2010-11 growing year, and when his home was searched on April 17 last year had a large amount of cannabis spread out to dry in a bedroom, plus 57gm of cannabis in sellable form.
In September, Frank Mathew Tainton, 61, was sentenced to two years and nine months' jail for his part in the ring, and an order was made for the forfeiture of his vehicle.
A 43-year-old Invercargill man has pleaded not guilty to 12 charges. A single charge against a fifth man arrested as part of Operation Canary was withdrawn.