I'm not even disagreeing with you, Stadler, I honestly don't know what you're saying. Who are Bruce, Clarence, Roy... wait, the E-Street band? That's Bruce's band. What would that have to do with a band like Dream Theater, a supposed collective? Bon Jovi is obviously Jon Bon Jovi's band, duh. But I don't know enough about AC/DC or Iron Maiden to know who the obvious one voice would be.
And I still don't see how that applies to Dream Theater. JLB is recording vocals. Both JP and MP are literally breathing on him, telling him what to sing and how to sing it. Whose is the one voice that counts?
Well, from everything I've heard, for AC/DC, Angus ultimately calls the shots, and the music gets put together the way
he ultimately wants it. In Maiden, the same goes with Steve Harris. When you have guys that have worked together that long, there is a lot of trust built up over the years that leads to a lot of freedom being given. So it may not look/feel like one person has the final say to someone on the outside. But that's still the reality when you get right down to it. I think Rumborak's analogy is pretty spot on:
Isn't this just what managers do in companies? That is, you have to strike the fine balance between enough guidance to get the best end result, but not micromanaging in order not to stifle people's creativity.
With DT, I think your view of them as a "collective" is inaccurate. I mean, it isn't a dictatorship. But when it comes to writing the music and the creative vision, not all voices are equal in the band, and it has been that way since day 1. Remember that when they started, the idea was that the instrumentalists (primarily JP and MP) called the creative shots. Charlie was told in no uncertain terms that, basically, his job was to come in and sing what he was told to sing, and stay out of the way to let the instrumentalists shine. Same thing with James when he was brought in. The tricky thing is, it's also real life, and expectations and how they are applied in real life change. They don't stay exactly the same, and are dynamic and fluid. So remember that by the time they got to the recording of SFAM, James basically decided that, since he didn't really have much input into the music, and would just come in and sing the parts assigned to him once the music was done, he would rather be outside playing basketball than be present in the studio when the others were writing/recording. And some or all of the others decided they didn't really like that. Hence, they told him they wanted him more engaged when it came to the SDOIT sessions. But still, going forward even from that point, John and Mike still drove the overall direction of the songs, including providing oversight and direction on a lot of James' vocals. It has basically ALWAYS been that way in DT, even if the amount of oversight and direction has ebbed and flowed from time to time.
Mike was part of that in DT. And that is the environment when Derek was in DT. So it is natural for them to have a similar model in SoA. And as far as we know, it is working for them, so it really isn't for us on the outside to say that it is somehow wrong.