As a MRD who tanked all 4 instances of the Beta with ACNs, I can safely say that it's either:
1) The ACN isn't really assisting because a Pikarbuncle should NOT take single target aggro.
2) The tank isn't marking which brings us to 1.
To be honest, though, we have an aggroed mobs window. Even if the tank isn't marking, it's easy to see which target is going down first. I personally am able to deal with Pikarbuncles (though I don't understand why I should have to... Seriously, 5 seconds cast, do it. Its "AoE damage" is crap.). The only time I really, really hate them is when:
Someone in the group runs ahead of the tank which is already chain pulling crap, and/or starts attacking before the tank pulled. Now the tank is already in emergency enmity mode. The ACN sicks his taunting pet on a target which isn't the main assist, AND that target happens to like doing frontal AoEs! Well guess what, the mob turns around to kill the Pikarbuncle, and casts his AoE on the group. GG.
It's not necessarily about just the tank being able to fight with a pet for aggro. It's about NOT NEEDING TO because it provides close to zero benefits and only strains the tank for no reason. When you think about it, in the grand scheme of things, wasting enmity cooldowns on a mob because a freaking pet taunted is so dumb. Specially in this game where Voke is on an 18 seconds CD. And then what? The healer should keep the pet up? The ACN should waste GCDs healing his own pet (sacrificing HP which could lead to having the healer heal the ACN)?
There is just no point to it. It's a quality of life thing and almost a respect thing. Why do something that's annoying to others for no real benefit? Just be a good ACN, and pull out your Emerald at the beginning of the instance. The healer has to cast Protect anyway so you're hardly wasting other people's time. You are in fact HELPING others be 100% in control of the situation.
Edited, Aug 19th 2013 2:04am by kirzansix
I find it interesting people are speaking of marking. The few times I did try this, the DD's had rushed in and pulled everything before I even got the first one marked. I barely had time to type anything in party chat before they were off pulling the next group. I gave up trying after a while, because it was just harder for me to run around and get all the mobs back. Most times, as a tank, if feels you are always on edge when trying to do anything for fear that you'll have to chase mobs around to get hate back on you. I can't even equip better gear from chests, not enough time. Have to wait til the run is over. I agree that marking is essential, but I don't expect it to be a viable option in PUG's, due to mosts impatient nature. Once game is out and people start getting a solid foundation of trusted acquaintances, this will be less of an issue, but until then, it is what it is.