Working with a group will be stressful. This is a case of too many cooks spoiling the broth. Instead of proposing alternatives, remain silent. There's no point wasting your energy on a pointless task. By keeping your head down, you'll be able to get through this trying time relatively unscathed. It pains you to watch a promising project go down the drain, but it's inevitable. When you're dealing with oversized egos like this, it's impossible to make progress.