I ponder this briefly in my upcoming comic rambling about the new LSH in June's Collector Times, and I thought I'd toss the discussion out to others.
The new Legion is essentially the original Legion, but it's not the original Legion as we last saw them circa 1994ish, before Zero Hour. When do YOU think they break off?
My biggest thing is that it has to be before the infamous v4, since Blok is still alive, so somewhere after or maybe even during v3. Did the Magic Wars still happen, or is the break sometime during the Five Year Gap? I'd have to dig through issues and look for other changes, but for now I'm running with somewhere in between volumes 3 and 4.
How cool would it be if these stories were actually leading us towards the events of the TMK era?