As far as identifying the alignments with actual political ideologies, identifying Neutral with anarchists makes more sense considering it's focus on autonomous action and humanist ideals. While they explicitly call Chaos anarchist on SMT4A it's fairly obvious that it was originally intended to be a parallel for japanese fascism and in most games it takes the form of some kind of enlightened anprim darwinism, particularly in Strange Journey. The true centrists are The White.
None of the Law-aligned options ever turn into straight-up slavery (from an economic point of view), but still, it really depends on the game. SMT4's version of Law, for example, doesn't end up requiring any enforcement of authority and resembles post-human communism more than anything else, directly changing 'human nature' itself to create a more peaceful, selfless and understanding society, where conflict is either non-existent or resolved without much issue. Obviously this doesn't really make sense from our
particular point of view, looking more like soft slavery than anything else, but then again, what makes returning to a previous, less organized state of humanity more appealing, exactly? Ultimately the way the megaten universe works means that even this return is just a temporary pause to the apocalypse, and that only the physically mighty (in the most literal sense) get to set the rules. So you might as well make sure that the good you do is permanent.