Jow Gar was founded by the five Jow brothers. The style primarily combines Hung Gar and Choy Gar with some northern influence. Since two of the five southern family styles (hung, lau, choy, lay & mok) are included that is the reason it resembles CLF. Most of the southern styles have some similarities to each other.
As far as Doc Fai Wong goes I think he initially followed Sifu Lau Bun for a short time and later followed Sifu Wong Gong. I read somewhere that the 5 animals form in the book is a Southern Shaolin form and never mentions that it is CLF.