There is no chance team composition changed, at least with respect to me and PsyHeal, I paid very close attention to make sure we were never split. I can't say with 100% certainty the other 6 spots stayed static. As the raid leader PsyHeal did do some juggling, I think, but the two of us were never separated.
9 is weird to me in that it's 3 * 3 and you get 3 merits per pylon and I think I missed 3 pylons. I don't have a paper trail for that so it's speculation, but not baseless speculation.