Here is a picture to start the conversation.
Like your artwork!
Since you guys covered Cobra here are some ideas for the Joes:
Duke: Original member of Darby's Rangers. Survived Anzio and transferred over to the 1st SSF.
Scarlett: Former OSS agent. If there is a Marvel Comics crossover she is a friend of Peggy Carter.
Lady J: American born former SOE Agent. After the war she returned to America and eventually joined G.I. Joe. Maybe she is like Churchill has a American mother and British father.
Both sides of her family are military families.
Flint: Another former member of the 1stSSF. Could be a Canadian who immigrated to America after the war and reenlisted in the US Army
Road Block: former member of the 761st Tank Battalion. Best BAR gunner in the Army
Snake Eyes: 82nd Airborne Paratrooper. Made all the division's combat jumps in WWII. Seriously wounded in Korea which is the reason he is disfigured.
Not pictured:
Gung Ho: Former member of Marine 2nd Raider Battalion.
Ship Wreck: Old Asiatic Fleet sailor. fought with the guerillas in the Philippines.
Recondo: former Alamo Scout