Li Jing
In 621, Li Jing submitted 10 strategies against Liang, and Li Xiaogong submitted them to Emperor Gaozu. Emperor Gaozu approved of Li Jing's plans, and made Li Jing Li Xiaogong's assistant in the campaign against Liang. It was said that as Li Xiaogong was still inexperienced, Emperor Gaozu actually put Li Jing in charge of most of the operations, although Li Xiaogong was formally commander of the operations.