There are many lawyers as GMs in sports, the Bucs won a Super bowl with a lawyer GM right before Lightning did.
You're making the presumption that a GM has to be a jack of all trades....they arent. Feaster handles the business side and has hockey experts around him.
The Bills for example use Football guys as GM and asst GM and a business guy to handle contract negotiations.
Feaster, btw, built the Hershey Bears, part of the reason he was executive of the year. With the Lightning he was in charge of scouting,.... you know, building the team. That's why a few years later the NHL GMs voted him executive of the year. Lawyers obviously suck at being GM