If I would have to place money on group A, I would choose the 1tes(2pp).
Have more of a history of high level competition than the others.
Not sure what history you are taking into account especially when the 3eVolt is in group A haha. But uhm yea i will say 2pp (1tes) is likely the current strongest in the group. But if we take battle records into account etc these matches are all going to be very hard to call as we have all likely played before and the matches were very close resulting in ties or 6-4's etc.
3eVolt is going to 3-0 their group.. They have brought back a bunch of amazing old meleers from old 3eVolt days. Also Grimsight definitely has the most experience leading, the 3eVolt team that is going to be playing in this tournament is going to clean up superior melee + superior leading = 3-0 3eVolt
Edit: I think it is going to be a really hard fight for 2nd place 2pp, psg and the 84e are all evenly matched in my opinion and all very competent regiments with competent leaders.