It can be less then 4/12 pitch but not recommended especially in areas with snow load.
What is the spacing on the strapping that the metal is screwed to? Would be good if it was 16" as your sheets of plywood or OSB are 4' by 8'
Some pole sheds are strapped on 18" or even 20" or 24". Which does not work well. You can add another strapping where needed for the edge of the sheets.