when looking for sources to learn, In the end you go with what works best for you and your groups party make-up. You can also mix match sources if certain phase mechanics dont mesh well with your group.

As far as dealing with mechanics, its always good to learn the bosses ability rotation to prepare for the tankbusters.as rhey are scripted.

Positioning, as their are multiple sources for learning the mechanics, their are also multiple ways to do the fights. Use the guides and POV to gain a general understanding and then communicate with your group to plan . This a MMO afterall