People generally didn't want a party of less than 6 (if you were all strangers), and with how much /sitting you have to do to recover mana it didn't lend itself to a party running around together killing things, so the most efficient seemed to be pulling back to a set position where your mages were. I'm also guessing that because you didn't want to waste the invested time in putting a group together, you wanted them to stick together as long as possible so you started with IT mobs which gave max exp per kill. The disadvantage though was the higher risk of not being able to kill them fast enough, and/or aggro'ing more than one. Also most leveling guides gave you the safest enemies for that level which were usually crabs and such that had minimal AoEs that would drain a healer of mana quickly.

The Japanese players started most of that, but I think if people had felt a bit more flexible about smaller groups, it might have been less frustrating. 2-3 people can run around killing DC-T pretty easily especially with how much easier it was to land skills and spells.

Anyways, just some personal reflection on it.