As I usually cast wish from memory there its needed to get round where you could drink poeh to restore your health to max. With ring and decent pv/dv on coward you could just summon these as even three molochs rarely harm you and you finish them faster.
Conserving mp is problem for other spellcasters, not wizards as you regenerate 5pp firebolts with basically infinite number of casting ipp bar stays full by just moving around. There is opposite problem that you need to cast expensive spells (like bookcasting teleport) to train mana.