To me, orderly evil has more to do with believing in structure and discipline. There are certain rules, but "no lying" isn't really one of them. Generally orderly vs chaotic is more about the overall personality of the character than the character's views with regards any particular ruleset. Does the character behave methodically, calculatingly? Orderly? Does the character go about helter-skelter without a lot of forethought and planning? Chaotic.

Only for certain characters (tribunals, outlanders) does the orderly/chaotic distinction relate to explicit philosophical principles.