The one sentence contains a noun, the other a pronoun, for the direct object.

French direct object pronouns, as well as others, are all clitics. See this answer for more detail.

In short, you can imagine that all the possible places a word can go in a sentence are like outlets and the various words are plugs (or whatever metaphor you prefer). A large plug can only fit in a large outlet and a small plug in a small outlet.

A noun phrase like les autres is a large plug. It carries new information. But a clitic like les that refers back to that is a small plug. It’s hardly a complete word in the eyes of the grammar system. It only carries information that is already known and “rounds out” the verb’s conjugation.

This may not be a very satisfying answer, but compare this behaviour with Spanish, a sister language, in phrases like ¿Puedes darmelo? The second word is actually three pieces: dar “give”, me “to me”, lo “it”. “Can you give it to me?” But those two details — give what? and to whom? — are seen as less significant and are tacked onto the end of the verb like suffixes. French (and other languages) see those details the same way.

As for your question’s original title… all languages are dense forests of rules and exceptions. 🙂 Whether we say there are a few broad rules and a lot of exceptions, or we say there are a million precise rules and no exceptions, the situation is the same: lots of elements behaving in lots of different ways. Actually, no language has yet been completed mapped out by grammarians, despite decades of effort, e.g. in the generative grammar tradition that Noam Chomsky started. However, since this particular case is pretty consistent in French — as Laure said, direct object pronouns come before the verb — I think we can call it a rule, even if it’s a perplexing one.