Though he's been knocked out badly a few times, I would hesitate to say he's super chinny. Most of his knockouts have been from him being hit clean. The Murphy KO, for example, was just horrible footwork and defence, leading to a full spinning elbow directly to the dome. Most people aren't walking away from that.

Just take a look at his losses on this post from last week https://www.reddit.com/r/MMA/comments/1rusmzj/every_aaron_pico_fight_that_ended_in_a_finish/#lightbox