''I don't rate WC from what I've seen. WSL yes. Jesse didn't rate William Cheung either.'' where did Jesse Glover say this? William Cheung trained harder than many of Ip Man's students, just look at his physique in his prime compared to WSL, Hawkins Cheung,Ip Chun, etc. Cheung's technique looks solid you can tell he has practiced, even though it includes a lot of ridiculous impractical things. WSL to be honest didn't look great compared to Cheung, WSL was no athlete and a chain smoker he never looked fast or that powerful or his technique very sharp. Just look at videos of him on Youtube such as the Instructional video he did in the early 1980's to see how he moved, same for people like Hawkins Cheung not much of an athlete and movement doesn't look too sharp.
Just because Cheung looked in better shape and his technique sharper doesn't necessarily mean he was better or knew more than WSL,Hawkins Cheung, Ip Chun, etc. Same for Jesse Glover or his brother Mike Lee, his brother Mike looked in better shape and more athletic but that doesn't necessarily mean better. Here is rare footage of Jesse's brother Mike, he looks powerful even if he is telegraphing most things by a mile! :
WSL knew the entire Wing Chun system, whilst it is questionable if William Cheung did know the full system or learn it all before leaving Hong Kong :
Some Wing Chun masters looks good at Chi Sau etc but not much good at anything else - when they free spar, attack from a distance, or do self defence, those that don't just look good at Chi Sau, etc often incorporate techniques from other arts too. Because Wing Chun doesn't require exceptional athletic ability, some don't train that hard as an all round athlete but if they did it would only serve to make them better.