Well, I wouldn't be saying that paladin goes last.
Everything that paladin does damage with, both physical and holy attacks depend/are increased by the weapon damage (except Exorcism and Consecration which are mainly PvE spells). The stronger the weapon damage, that stronger SoR hits are, stronger Judgement hits, stronger Crusader Strike and Divine Storm. Also, Crusader Strike and Divine Storm being physical damage benefit from arpen, sure, not the main stat, but having arpen on item isn't completely useless and you do benefit from it and sure as hell is more useful than say Gloren's expertise.
So I'd either put warr>pala>dk OR warr>pala=dk