I think the one thing 3-5-2 would do at the moment is
a) protect Kane or Son
b) allow Kane, Son or Richey to play closer to each other
I would love to see
Sees Bent PEH Deccy Perisic
as a 5 personally, but understand that Antonio won't do it. Perhaps it would be a way to switch things mid-game sometimes? Would allow one of our three forwards to always be an option off the bench, and rest one, further, with Skipp and Bissouma on the bench we could always opt to go defensive. I think Deccy almost floating as a creative 10 behind Kane and Son could absolutely work.
Of course, what is probably most important to realize is that 3-5-2 is only going to be an option used sparingly, further 3-4-3 will be Antonio's dominant.
The only thing which could force his hand is injury. I wish we'd find Harry some rest. I am worried.