Wu Long did not need to persuade Luo Mingyu's parents as General Feng was the one who did most of the talking. Not to mention that the beauty has been subtly preparing them all the while she stayed there.
The Patriarch of the Luo House, her grandfather would not budge, as he was a man of tradition and strict discipline. But since his old friend who would normally be driven by honor and tradition himself was the one asking, he understood that the situation was not as easy as it seemed.
His decision was something Wu Long more or less expected, which was to let the younger generation of his children and their peers as well as their descendants join their side while he and the old fossils of the Luo house, the previous generation remained in their place, fulfilling the duty of the house to the Kingdom, even if it meant burning with it.