Currently all the classes sans NIN has an instant enmity dump. NIN can transfer their aggro to another member in their party but that shouldn't be too much of a problem for them lacking an enmity dump. If you are actually having trouble keeping aggro it's either that your gear isn't up to par (I doubt), the DPS is doing crazy high damage or DPS isn't using aggro management. If it's the third, feel free to help them drop aggro :>