When you compare forms with the same name, they are completely different in terms of content and sequence. It's almost as if they are different styles.

Tat Mau Siu Mui Fah
https://www.youtube.com/watch?v=MxOhKTpWqKU

Doc Fai Wong Siu Mui Fah
https://www.youtube.com/watch?v=YLFzV4b2Csc

Chan Family Siu Mui Fah
https://www.youtube.com/watch?v=ocr5SPFNQbQ

This has bothered me for a long time. In other systems there will be differences in how forms are executed, but the basic postures are similar and follow a similar sequence.