I don't mind Numina at all. Doing it solo can make the hunts a little more painful waiting for teleport powers to recharge, but otherwise splitting up is efficient. I have seen several leaders ask for players to double up in zones starting with Faultline, not due to difficulty but simply due to larger numbers required. I tend to hit at least 5 of the zones since I hate sitting idle.
Unfortunately, at least for me since it's a pet peeve, I do somewhat frequently see people camping in Talos, FF and even Eden. If the leader or someone else on the team posts the list in team chat and someone still camps at one of the later zones, I'll make a note. I usually won't say something unless I'm leading, but will support someone who does make a comment. I usually say something simple, like 'There are 14 zones listed in order and 8 of us going on the team. Nobody should start at zone 9 or later.' Sometimes there will be an apology and a zone change. Otherwise I'll make notes and when the person asks to join a Numina I lead in the future, I'll make them aware of the note and simply not invite.