Oh well, back from the pool. I realize what I wrote was stupid... you need to generate force from your arm that is for sure, especially if you score a 55s per 100m, even with magical feet... it would be dark magic... lol
Now as an exercise I think pulling from the back (core) and trying to minimize the drag from the arm outsweep and insweep is indeed a good exercise as I think it helped me to use a better way.
I' m not sure what about what I'm doing now but it is "tighter" and feels more efficient.
A dominant feeling is that when I break the streamline I instantly feel pressure in my palm (each facing a side of the pool) and the pressure is maintained as I "flip" them as my elbows are getting to my core body. I'm careful not to let the movement get my hand deep in the water and I also notice that I stop the motion to get into fast and proper recovery (elbow within the width of my body) then I spear forward. If I do the motion to completely it generates too much turbulence and elevation I find it detrimental to the forward motion. The outsweep is minimal which does not mean that I don't feel water pressure in may hand while doing it.
Now I've no idea if Peaty does this or that /enthusiast beginner caught into over thinking... lol