It depends on the content you're doing, though. What do you need to know as an off-tank to do A1N? Voke .5 when it appears and tank it opposite of the original. That's extremely easy and you can go in blind for that fight and I'll explain everything you need to do in one sentence.
Now go to A3N as a tank. What do you need to know? The boss has 3 forms. The hand has cleaves that share damage. The hand splits into 2 parts and they must be tanked facing opposite ways. When he turns into a water spout, you have to take the tethers away from other players. For the magnets, opposites attract and likes repel. The 2nd part of the humanoid phase will have stacking vulnerabilities on you a-la-Shiva EX so a tank swap will make things smoother.
See the difference in things that need to be explained? An A3N explanation is still extremely light compared to fights like T9, so I won't even go there and instead use this very simple fight to get my point across. What's going to happen if you tank A3N going in blind wanting to "figure things out by yourself" when the fight is no longer new? The MT will have to turn the hand on the group because you don't know about the damage sharing, depending on how fast you react, the MT may be tanking both hands for a while, you won't know that you have to pick up tethers, but your commons sense may save you for the magnet mechanic. Not doing any of the things above, though, will just make the MT have to work harder to pull a victory out of the group because you couldn't be bothered to watch a 3 minute video guide, and if both tanks are in the same boat, then forget about it. Either that, or have someone in the group explain the fight to you after the first wipe because you didn't want to "watch someone else do it for you", except this is what's happening right now by having a group member explaining the fight for you, only difference is that you could have also done this on your own time.
It's expected to wipe on a fight when it's first released. Everyone is new and they're all still learning, but a month into content and still getting people going blind into fights that require explanations longer than a minute, then it gets to be a little tedious and honestly, you'll most likely die and end up being carried anyway, unless your failure to adhere to a mechanic has repercussions beyond your own death and you take the rest of the group down with you.
When going into a fight I don't know, I'd personally rather have some consideration for the 7 other people in my group and watch a short video (if the info is available, of course) so I know what's going to happen instead of having someone in the fight spoon feed me all the information, but hey, that's just me.
