You seem to be assuming hereif I'm playing a game that is actually heavy on role playing, and not just combat and only intend to have 2 or 3 FIGHTS all day, I have to make them insane, because they will be completely full when they hit those 2 or 3 fights.
Contrary to the tactical nature of some games, MANY people do have roleplaying encounters, where no spells will be used
(i) that combat encounters don't invovle roleplaying, and
(ii) that noncombat activity (social encounters, exploration) doesn't consuem spells.
My own experience in playing D&D (B/X, AD&D and 4e), and also Rolemaster, is that this is not true.