There is no way to allow each limb to do its own thing

What? Why not?

It's physically possible in terms of limb motion. It's very difficult for most people to actually do, sure; but impossible?

or the brain not to decide what comes next in a unified way

There's the idea that a lot of the brain's "conscious decisions" are actually post-hoc rationalisations of unconscious decisions. If so, there's no reason those decisions have to be unified. Maybe the consciousness of the decision and its outcomes must be unified; maybe that's somehow connected to what consciousness really is. Or maybe not!

I don't think there's enough information to say.