Sorry for my ignorance, but what are lat sau "sections"? I don't think I've ever come across these in my experience...
The EWTO ( European Wing Tsun Organization),the HQ of which is in Germany, is headed up by Keith Kernspecht, a direct student of Leung Ting.
KK came up with several programs (or sections) of lat sau to be taught to WT students at the beginning of their training to accelerate the learning process giving new students a pretty good grasp on how WT fights, early in their training.
Each program was taught at a different student level and were numbered accordingly.
So student grade one would learn program one of lat sau and so on.
In the US, the early WT groups were directly under LT and did not learn this German way of doing lat sau. They learned the Hong Kong method. Later generations of WT in the US learned the German way as European instructors came here and passed it along.
As an example, program one deals with straight line punching attacks at high, middle and low,along with low kicks to the legs.
Fifth program deals with knees and elbows and so on.