There don't seem to be a whole lot of people who agree with you about this whole "Tarquin and Shojo should have similar alignments," thing jftr; there are a number of counterarguments to your analysis that you have not addressed (which, admittedly, is understandable, since there have been many from multiple sources).
But the results of that sort of arguing aside, what, exactly, is the problem here? You said it doesn't detract from the story; what other reason is there to care, say, about how much Shojo's proven his alignment to be Chaotic Good? I fear I may be misunderstanding your point here, because it sounds like you're concerned that people will misunderstand the DnD alignment system from reading the comic, and I neither think that is the case nor that it would really matter anyway.