I’m pretty sure you stay in the same subs as the people in your main PvE. The thing is when looking at the top X, it could be the people that were in the last sub just haven’t started it yet or aren’t as active after it started. It’s also possible that the person who has that max’d 4*'s is grinding earlier rather than being optimal.
i mean in sub 2 I can see the top 15 (14th now) and not a single one of these top 15 are even in my top 18 in main,
Then again i dont think you will stay in same bracket in sub events cause every bracket is 1000 just noticed that. so i think its the first 1000 that join at that time is put in the new sub brackets.
Seems like the leaders in sub 2 are grinding the nodes early, while the overall event leaders are playing more optimally, hitting the nodes only every 8 hours. Check again at the end of the sub, you’d except to see mostly the same people in top 10 for the sub and the overall event.