The most typical setup for the merge I've been experiencing lately is me at a medium altitude--say 10-12K, with an enemy around 1-2K above me, with us both approaching the other from the 12 o'clock position. At a distance, and before we merge, say around 1.0-2.0 icon range, I see him roll inverted, and pull into me. Most of the time, we're both at a combat cruise speed, so both aircraft are carrying a decent amount of energy. They always pull for the HO shot, and undoubtedly miss as I jink the HO, then pull up in a zoom. At this point, most of the time they either roll back and extend away behind me or pull through and complete the split-s and wind up underneath me. Either way, it always seemed to me, they blow they're opportunity to shoot me down. As I'm typically in a Jug, if they split-s, I can catch them in a dive if so inclined.
My point in asking the question was to determine if there was any advantage at all in them approaching the merge inverted like that.