While I understand where your coming from, I do think it depends on the individual player, and how he's willing to sacrifice. I heard this same argument when Boston brought Garnett, Pierce, and Allen together with Rondo. However it worked out just fine because all those players were willing to set their ego's aside for the good of the team. Same argument was made in Miami. Not saying that the talent level equates, but the ego's probably do. So I don't think you can use a blanket statement to predict the outcome. You could be right, but there's no certainty in that. One thing I'm certain of, is that it would be a better team, if only by accident. And I'm on board with anything that makes us better.
It's one thing to have a vision of what you want to accomplish, but it's quite another to metaphorically be on a desert island, dying of thirst, and have someone offer you a gatorade, and you turn them down because it's the wrong flavor.