wrist series progression question

I could've sworn I saw a thread about this a while back, but now I can't seem to find it, so I apologize if this has already been discussed.  As I'm going through the wrist series progressions, I can't help but wonder why it goes PE1-4 then SE1-4 instead of PE1, SE1, PE2, SE2, etc.  I'm currently on PE3 for each, taking my time going through the cycle and may even repeat the last 4 weeks after this cycle.  It seems to me that it would be easier to transition from PE3 to SE3 than it would to transition from PE3 to PE4, and it definitely seems like SE1 and SE2 would be much easier than PE4.  Did anyone progress like this instead, or should I stick to course as it was written?  Am I underestimating the increase in difficulty between the walking version and the pushup version of each position?

Yes you are.

The progression moves from one wrist at a time (walking)to both together. In the most stressful parts if the rep, that can make a big difference !(having said that, I moved through SE1 and 2 very quickly)

If in doubt, probably best to follow the course as written :-)