I dont know about the gang scene in Hamilton. Its does make sense about jamaican gangs operating in the city, since its a couple of hours from Toronto.

Woolley got around Mom Boucher, like many other haitians or jamaicans got around people like rizzuto or members of the irish mob.
Montreal is a small city, so when you got a group of criminals who have the capacity to make money or hits, you will have the chance to meet and be part of big players.
During the biker war between the Hells and the Rock Machine, haitian gang members were also picking side during the war. The CDP’s align themself with the Hells , and the BO’s align themself with the Rock Machine. And many bikers were killed by haitian hitmen that sere doing hits during the war. Woolley was one of those guys. He was doing hits, but was also a very good buisness man and leader. So people like Woolley and Goodridge became more and more connect with the Hells, because they were simply good.
They are probably other haitians, jamaicans or ethnicities that are very powerful in the montreal criminal world, we just dont esr about them