After having run it a few times with Warrior nation, i can say that yeah, defending sucks...
The raid leader generally has to be on the ball at all times and NOT get into engagements. He has to always be able to keep track of the mobs. If the leader gets into a fight it's generally bad news, usually then he'll be yelling for someone to keep an eye on the gate or reinforce the gate.
I wonder if they at least got past the Ghost Town part... That part is easy if you have ppl who can follow instructions. All you need is two defense groups at the gate, two, ideally 3 offensive for the 2 towers and enemy gate. Gate defense groups have to sit by the gate and DO NOT ENGAGE mobs. Everyone ELSE's job is to clear mobs. If the gate gets tagged, join the fight (reinforce gate) and kill the mobs while healing the gate. Once it's obviously clear that the gate is safe, one of the two defenders can move out and help clear mobs. There should always be one on standby to reinforce the gate at all times.
Offensive groups should move right to their allotted towers/enemy gate ASAP, do not engage the trash, and report in nation chat as soon as the towers/gate is tagged, and when they're down. An idea is to kill the gate and ONE tower, leave the other one up. Once the enemy gate is down the creeps stop spawning. Clear mobs in Ghost Town and move back to the Pirate Ship's Grave, then start stepping on all the octo. Once all mobs are cleared, the group can enter the Damp Cabin. Nothing will spawn until the remaining tower is killed, so it gives the group some time to spread out in the cabin and get into position before the tower is released (dropped).