I think admittedly you're reading too deeply into a line from a film. It was fictional and added for context. Gribbs was being used as a timestamp to mark to most recent major drug arrest in that time period to be used an an example. Also worth noting is that Paulie was having an affair with Karen while Henry was in prison. This is largely the point of contention for his issue with Henry IMO.
Nearly every single member of Paulie by extension was involved in drugs in one way or another. Either financing or outright trafficking. Paulie loaned a LOT of money on the streets but at this point in time had few other rackets going. If his guys couldn't earn on their own, they weren't making any "real" money. I also restate my point of how disconnected Paulie was from the streets. There wasn't some oversight committee to judge the mobsters who were privately dealing drugs. Paulie logically wouldn't have known until it was too late, because he was too far removed from the street level and as well seemingly slightly out of tough with the modernizing rackets as the book seemed to have framed him as an aging paranoid.
Literally every member of Jimmy and his crew were dealing. Jimmy with Henry. Then afterwards with Tommy D, then with Angelo Sepe and others. It's not that they didn't want to kill Henry, as I stated earlier, I simply feel they acted too late.
The Trumanti line referred to a case in which an agent testified that Trumanti shaking hands when saying hello to a man in a restaurant was a signal that the man could proceed with a drug deal.
