Ye Xiu found An Dongye's move quite impressive, not because it could simultaneously deceive Lin Mu and the civilian martial artists into going to Nameless Island to die.
In fact, the task of Lin Mu and the civilian martial artists was simply to buy time. Whether or not they eliminate the enemy is secondary, as long as they can delay until the martial artists' allied forces, the Heavenly Sect, Hell's Gate, the Restorer Alliance, the Prisoners' Descendants Alliance, and Lin Feng finish their wars on the various islands, and gather forces at Xiaoyao Island.
Moreover, gathering Lin Mu and so many civilian martial artists on Nameless Island means that the Blood Cloth Guards and the 101st Squad would take a long time to kill them all.
This would also affect the progress of 'Spiritual Energy Infusion'.
In short, An Dongye's move is like taking off your pants to fart — unnecessary!
