It's strange that people can take two arguments and conclude no question that one is right and another is wrong. So the cleave feat says you can make an extra melee attack per round. So what? The AoO rule says you can only make one per round. So who is to say which is the correct ruling? It's just a matter of opinion.
The primary reason I do not allow it imc is simply because, as already pointed out in this thread, if someone drops their guard and takes an AoO it has nothing to do with anyone else and using cleave in this way just seems, to me, to make a mockery of the rules.
The primary reason I do not allow it imc is simply because, as already pointed out in this thread, if someone drops their guard and takes an AoO it has nothing to do with anyone else and using cleave in this way just seems, to me, to make a mockery of the rules.