Alton said Simpkin was ahead of his time, always looking at ways to evolve the game of rugby, changing the way the game was played and lobbying for changes to the laws.
"But unbelievable rugby brain aside, George will be remembered mainly for his care and concern for anyone he met often asking them. 'Where do you want to be in five years? What are you going to do when you go back to New Zealand? Imagine if rugby was played by the PLA (People's Liberation Army)?'"
Alton said Simpkin made his mark mainly in Waikato Rugby circles, coaching Matamata College 1st XV and taking them on a 50+ game winning streak. He went on to coach the Waikato Senior team for 9 years, gaining promotion to the NPC 1st Division and capturing the Ranfurly Shield against Auckland in 1980.
"His greatest impact on rugby was to come. George and Pip moved to Hong Kong in 1990, to take on the rugby director role with Hong Kong Rugby Union.
"During the 17 years there; he coached the National 15s and sevens teams, established new rugby clubs run by local Hong Kong Chinese. He also promoted women's rugby, developed rugby training programmes in schools and universities.
"In his most forward-thinking move, George established strong links in mainland China where, along with his good mate and work colleague KK Chu, they encouraged the PLA to develop a rugby programme."
Alton said Simpkin also had coaching roles in Fiji, Sri Lanka and was influential in encouraging rugby to be established in countries like Pakistan and throughout Asia.
Simpkin had strong links in the Bay of Plenty, living in Tauranga and purchasing kiwifruit orchards.
"He was a regular at any sevens Tournament that was run in New Zealand and around the world. George particularly loved the National Provincial sevens, played in recent years in Rotorua and Tauranga. He always admired the amount of talent on display from around the country."
While in Hong Kong, Simpkin built a lifelong friendship with Fiji rugby legend, Waisale Serevi.
"Serevi would always meet George prior to the Hong Kong 7s Tournament, often over a bowl of kava and talking all things rugby for hours on end.
"He was a man of great mana and he will be missed," Alton said.
Simpkin is survived by his wife, children Leigh and Greer, and grandchildren Carter, Holly and Curtis.
There will be no funeral at this stage but the family asks people to please light a candle in his memory instead.