To elaborate on my post just a little:
- FTE enforced - can't steal mobs
- LnS - can't corpse camp key raid members
- No Item Loot - can't take pixels from the raiders
- Plugging - raiders can always run and hide
- No training - can't use mobs to even the odds between a small and large force
- Resist Code - AoE, roots, and other strategies for dealing with larger forces and better geared players are resisted 98% of the time with even low MR.
- OP melee gear - better geared players have a huge advantage (classic, as in pre-kunark, wasn't like this)
- No limit to guild size or raid size, and it's easy to hand loot to whoever the raid decides should get it - zerging is possible.
Like I said, the zerg is inevitable. If the devs ever want to change that, they'll need to change the rules.