Probably not. Just make sure to bind your skills, keep shield block up, demo shout to reduce physical damage…
When you have threat on an un CC’ed caster, and the DPSer is tunneling on the disarmed phys dmg mob that you have a sunder on, and had threat on but obviously isn’t your primary kill target, you’ll know it’s the DPSer tunneling.
You can always make a macro and bind marks, if you’re playing with people who are new and need that sort of thing.