You make a good point, but:
a)a potion can't be used from a distance as opposed to spell (higher flexibility for casters as opposed to non-casters, same as what I'm suggesting for arrows)
b)as is: the amount of healing potions and food is imho too high in the game
c) clerics have MANY other tools than just healing (which is cheapened by the omnipresence of scrolls everywhere as of right now). Spell variety can't be compared to rangers-only abilities which are very few.
