If the punch and footwork are the same thing then you won't have any choice but to train both of them at once. Jow Ga's big punches can't be broken down into 2 separate components. Both have to be trained together. The swinging of the arms actually helps to develop the footwork. It's always a train wreck that lasts for months and sometimes years, before students can do it correct.
Jabs go a little easier because it's something students an focus on without confusion from other types of movement. If the student doesn't know how to punch or at least imitate the movement of a punch then you can forget about the footwork working. This is pretty much what I do by default now. I watch people punch and then I try to correct and explain how to punch. How much I explain depends on how frustrated they look when I start correcting.
If the punch and footwork are foreign movements then their brains are going to explode lol.
Here is a beginner's Jow Ga Class. Brains all over the place (This is punch + footwork training). After you sweep up the brains you have to go back and manage any frustration that students may be having so they don't quit. This usually requires breaking movements into pieces and giving them bite size things to work on. A bad punch can weaken the stance, bad footwork can weaken a punch.