I’d personally go with reducing the slots to 1/3
It sounds good on first but on the other hand reducing slots to one can lead to some problems if person switch from shield and one hander to two handers or bow/xbow. So weapon or shield will be dropped on ground?
I think leaving 2 basic bag slots with fatigue reduction for items in it and making 4 slots and no max fatigue reduction for perk will be the simplest choice now.
Four slots is kinda overkill though.