I would say that Modrons are neither good nor evil, only lawful. They aren't doing what they do because they want to do it, they're doing it because they're programmed to do it. They have no ulterior motive, just orders that they must obey. Today it might be "wipe out that town", tomorrow it's "pick daisies and give them to those orphans".

Or, you could just use the statblock as a chassis for any sort of programmed automaton (that's not a golem) and disregard the fluff.