The snake crane wing Chun of sifu Wayne Yung and YKS lineage are sister linege from red boat pre 1900.
Yes, snake crane are applied to all red boat lineage WCK.
Henry Leung Lineage is a different evolution.
From your description , the lineage you learn, seem to be an evolution instead of the direct red boat opera actor related lineage or post 1900 WCK.