Complex sentence: The armed forces of the Aitolian League are peculiar as compared to other Greek states in the fact they barely used at all any mercenaries, in fact it was more likely for Aitolian to be exported abroad as mercenaries.
Split into simpler sentences: The armed forces of the Aitolian League are peculiar as compared to other Greek states in that they rarely used mercenaries. In fact, it was more likely for Aitolian to be exported abroad as mercenaries.